Algebra Function Basic Flashcards

1
Q

In algebra, how is a function defined in simplest terms?

A

A rule that assigns each input exactly one output.

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2
Q

What is the ‘domain’ of a function f?

A

All possible input values (x-values) for which f(x) is defined.

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3
Q

What is the ‘codomain’ of a function?

A

The set in which all outputs of the function are allowed to lie.

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4
Q

What is the ‘range’ (or image) of a function?

A

All actual output values the function produces from its domain.

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5
Q

What does it mean for a relation to ‘fail the vertical line test’?

A

At least one vertical line intersects the graph in more than one point, so it is not a function.

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6
Q

Define a ‘one-to-one’ (injective) function.

A

A function where each output is produced by at most one input (distinct inputs → distinct outputs).

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7
Q

Define an ‘onto’ (surjective) function.

A

A function whose range equals its entire codomain (every element in the codomain is mapped from some input).

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8
Q

What does ‘bijective’ mean for a function?

A

It is both injective and surjective, so it has a perfect one-to-one correspondence between domain and codomain.

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9
Q

In function notation, f: A → B, what do A and B represent?

A

A is the domain, B is the codomain.

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10
Q

What is the difference between ‘range’ and ‘codomain’?

A

Range is the actual set of outputs. Codomain is the set from which outputs can potentially come.

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11
Q

How do you typically find the domain of a function given by an expression?

A

Identify values of x that make the expression undefined or invalid (e.g., dividing by zero, negative radicands for even roots), then exclude them.

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12
Q

How do you find the domain of a rational function f(x) = P(x)/Q(x)?

A

Exclude values for which Q(x) = 0 from the real domain.

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13
Q

What is the domain of f(x) = √(x - 3) in real numbers?

A

All x ≥ 3.

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14
Q

What is the domain of f(x) = 1/(x + 2) in real numbers?

A

All real x except x ≠ -2.

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15
Q

If f(x) = √(x + 4) + (1/(x - 2)), how do you determine domain?

A

First x + 4 ≥ 0 → x ≥ -4, and x - 2 ≠ 0 → x ≠ 2. Combine to get x ≥ -4 but x ≠ 2.

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16
Q

Give an example of a function with domain all real numbers ℝ.

A

Any polynomial, e.g., f(x) = x² + 1.

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17
Q

How do you typically find the range of a function algebraically?

A

Solve y = f(x) for x in terms of y, then determine permissible y-values (sometimes more advanced).

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18
Q

What is the range of the function f(x) = x², x ∈ ℝ?

A

All real y ≥ 0.

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19
Q

What is the range of f(x) = 2x + 3, x ∈ ℝ?

A

All real numbers (−∞, ∞).

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20
Q

For f(x) = 1/x, x ≠ 0, what is its range in real numbers?

A

All real y except y ≠ 0.

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21
Q

Define a linear function in one variable.

A

A function of the form f(x) = mx + b, where m and b are constants.

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22
Q

Define a constant function.

A

A function where f(x) = c for all x in the domain, c is a constant.

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23
Q

What is a polynomial function?

A

A function f(x) = aₙxⁿ + … + a₁x + a₀ where coefficients aᵢ are real numbers and exponents are nonnegative integers.

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24
Q

Define a quadratic function.

A

A polynomial function of degree 2: f(x) = ax² + bx + c, with a ≠ 0.

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25
Q

What is a cubic function?

A

A polynomial function of degree 3, e.g. f(x) = ax³ + bx² + cx + d.

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26
Q

What is a rational function?

A

A function that can be written as the ratio of two polynomials, f(x) = P(x)/Q(x).

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27
Q

Define a piecewise function.

A

A function defined by different expressions on different intervals of its domain.

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28
Q

Define an exponential function (with base b>0, b≠1).

A

f(x) = b^x, domain = ℝ, range = (0, ∞).

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29
Q

Define a logarithmic function (base b>0, b≠1).

A

f(x) = log_b(x), domain = (0, ∞), range = ℝ.

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30
Q

What is an absolute value function in standard form?

A

f(x) = |x|, which outputs the nonnegative magnitude of x.

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31
Q

What is the signum (sign) function?

A

sgn(x) = 1 if x>0, 0 if x=0, and -1 if x<0.

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32
Q

What is the greatest integer (floor) function?

A

⌊x⌋ gives the largest integer less than or equal to x.

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33
Q

What is the fractional part function?

A

{x} = x - ⌊x⌋, the ‘decimal part’ of x.

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34
Q

Define the step function f(x)=c for intervals, e.g., the Heaviside step function.

A

Heaviside: H(x)=0 if x<0, 1 if x≥0. It’s a piecewise constant function.

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35
Q

What is the identity function on ℝ?

A

f(x) = x for all x in ℝ.

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36
Q

What is the zero function on ℝ?

A

f(x) = 0 for all x in ℝ.

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37
Q

Define an ‘even’ function in terms of symmetry.

A

f(−x) = f(x) for all x in domain; symmetric about the y-axis.

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38
Q

Define an ‘odd’ function in terms of symmetry.

A

f(−x) = −f(x) for all x in domain; symmetric about the origin.

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39
Q

Give an example of an even function.

A

f(x) = x².

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40
Q

Give an example of an odd function.

A

f(x) = x³.

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41
Q

What is the vertical line test for a function’s graph?

A

Any vertical line should intersect the graph at most once for it to be a function.

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42
Q

Define a horizontal shift for a function f(x).

A

g(x) = f(x - h) shifts f(x) h units to the right if h>0, left if h<0.

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43
Q

Define a vertical shift for a function f(x).

A

g(x) = f(x) + k shifts the graph k units up if k>0, down if k<0.

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44
Q

Define a horizontal scaling for a function f(x).

A

g(x) = f(bx). If |b|>1, it compresses horizontally; if 0<|b|<1, it stretches.

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45
Q

Define a vertical scaling for a function f(x).

A

g(x) = a·f(x). If |a|>1, vertical stretch; if 0<|a|<1, vertical shrink.

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46
Q

How do you reflect a function across the x-axis?

A

Use g(x) = −f(x).

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47
Q

How do you reflect a function across the y-axis?

A

Use g(x) = f(−x).

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48
Q

If y=f(x) is known, what function form flips the graph over the line y=x (i.e., reflection across y=x)?

A

The inverse function, x = f(y) solved for y, or y = f⁻¹(x).

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49
Q

How is the graph of y=f(x)+3 derived from y=f(x)?

A

Shift it up by 3 units.

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50
Q

How is the graph of y=f(x−2) derived from y=f(x)?

A

Shift it right by 2 units.

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51
Q

Define the sum of two functions f and g.

A

(f + g)(x) = f(x) + g(x).

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52
Q

Define the difference of two functions f and g.

A

(f − g)(x) = f(x) − g(x).

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53
Q

Define the product of two functions f and g.

A

(fg)(x) = f(x)·g(x).

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54
Q

Define the quotient of two functions f and g, g≠0.

A

(f/g)(x) = f(x)/g(x), domain excludes where g(x)=0.

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55
Q

Define the composition (f ∘ g)(x).

A

f(g(x)). First apply g, then apply f to the result.

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56
Q

What is an example of function composition usage?

A

If f(x)=2x+1 and g(x)=x², then (f ∘ g)(x)=f(x²)=2x²+1.

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57
Q

How do you find the domain of (f ∘ g)(x)?

A

Include only x values in the domain of g for which g(x) is in the domain of f.

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58
Q

What property must hold for function composition to make sense?

A

The range of g must overlap with the domain of f.

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59
Q

Is function composition generally commutative?

A

No; (f ∘ g)(x) usually differs from (g ∘ f)(x).

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60
Q

If h(x) = (f + g)(x), how is this typically simplified?

A

h(x)=f(x)+g(x). Keep domain constraints in mind from both f and g.

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61
Q

Define an inverse function f⁻¹ if f is one-to-one.

A

A function that undoes f, satisfying f⁻¹(f(x))=x and f(f⁻¹(x))=x.

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62
Q

What is the key property that allows a function to have an inverse?

A

The function must be injective (one-to-one).

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63
Q

What is the graphical relationship of a function and its inverse?

A

They are reflections of each other across the line y=x.

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64
Q

How do you find an inverse function algebraically?

A

1) Write y=f(x). 2) Solve for x in terms of y. 3) Switch x and y, get y=f⁻¹(x).

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65
Q

What is the domain of f⁻¹ compared to f?

A

It is the range of f.

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66
Q

What is the range of f⁻¹ compared to f?

A

It is the domain of f.

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67
Q

If f(x)=2x+5, find f⁻¹(x).

A

f⁻¹(x)=(x−5)/2.

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68
Q

For f(x)=x³, find f⁻¹(x).

A

f⁻¹(x)=³√x.

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69
Q

If f(x)=|x|, is it invertible over ℝ?

A

No (it fails injectivity). Usually restricted to x≥0 or x≤0 for an inverse.

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70
Q

Is the function f(x)=x² invertible on all real ℝ?

A

No (it’s not one-to-one). Restrict domain to x≥0 or x≤0 to define an inverse.

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71
Q

Define ‘increasing function’ on an interval.

A

f(x₁) < f(x₂) for all x₁ < x₂ in that interval.

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72
Q

Define ‘decreasing function’ on an interval.

A

f(x₁) > f(x₂) for all x₁ < x₂ in that interval.

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73
Q

Define a constant function on an interval.

A

f(x₁) = f(x₂) for all x₁, x₂ in that interval.

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74
Q

What is a local maximum of a function?

A

A point where f(x₀) ≥ f(x) for x near x₀.

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75
Q

What is a local minimum of a function?

A

A point where f(x₀) ≤ f(x) for x near x₀.

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76
Q

Define a continuous function at x=a.

A

f is continuous at a if lim(x→a) f(x)=f(a).

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77
Q

Define a discontinuous function at x=a.

A

A function that breaks the continuity condition (limit doesn’t exist, or doesn’t equal f(a)).

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78
Q

Explain boundedness of a function on an interval.

A

It’s bounded if there’s a real M with |f(x)| ≤ M for all x in that interval.

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79
Q

Define the zero (or root) of a function.

A

An x-value such that f(x)=0.

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80
Q

What is the difference between local and global extrema of a function?

A

Local is highest/lowest in a neighborhood; global is highest/lowest over the entire domain.

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81
Q

What is a piecewise-defined function? Give a simple example.

A

Defined by multiple rules on different intervals. E.g. f(x)=x if x≥0, −x if x<0.

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82
Q

When combining piecewise functions, how do you handle domain overlap?

A

Match intervals carefully and define sums/products piecewise as well.

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83
Q

Explain function iteration, e.g., f²(x).

A

f²(x) means f(f(x)), applying f to x twice.

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84
Q

What is the functional equation approach in basic form?

A

It’s an equation like f(x+y)=f(x)+f(y), used to deduce function forms (like linear for additive).

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85
Q

Define the identity function i(x) on domain D.

A

i(x)=x for all x ∈ D.

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86
Q

Describe how to reflect a function across the line y=k.

A

Subtract from k: new function is 2k−f(x).

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87
Q

Describe how to reflect a function across the line x=h.

A

Replace x with 2h−x in the function rule.

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88
Q

If f is one-to-one, how many times will a horizontal line intersect its graph?

A

At most once (the horizontal line test).

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89
Q

If f is onto a set B, what does that mean about the range of f?

A

Range = B exactly.

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90
Q

Why is f(x)=x² not injective on ℝ?

A

f(−1)=f(1)=1, so multiple x’s produce the same output.

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91
Q

Replace x with 2h−x in the function rule.

A
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92
Q

For a cost function C(q)=fixed cost + variable cost·q, what is the domain?

A

q≥0 (assuming no negative quantity).

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93
Q

If f(t)=distance traveled at time t, what is typically the domain?

A

t≥0, as negative time is not used (depending on context).

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94
Q

In a supply/demand function, p=f(q), domain is q≥0. Why?

A

Quantity q can’t be negative.

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95
Q

If f(x)=celcius from Fahrenheit, domain is all reals. The formula is f(F)=(5/9)(F−32). Range?

A

All real Celcius values: (−∞, ∞).

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96
Q

A parent function might be g(x)=x². Then h(x)=x²+3 is a vertical shift. Which direction by how much?

A

Up 3 units.

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97
Q

An inverse variation model is f(x)=k/x. If x doubles, how does f change?

A

f is halved, since f(x)∝1/x.

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98
Q

If f is even, then the graph is symmetrical about which axis?

A

The y-axis.

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99
Q

If f is odd, then f(0)=0 is typical. Why?

A

Because f(−0)=−f(0) implies f(0)=−f(0) → f(0)=0.

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100
Q

If a function passes the horizontal line test, what property does it have?

A

It is one-to-one (injective).

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101
Q

Give a direct variation function formula that passes through (0,0) with slope 5.

102
Q

What is a function transformation in algebra?

A

An operation (shifting, scaling, reflecting) that modifies a function’s graph into a new position or shape.

103
Q

Write the general form for a transformed function from a parent f(x).

A

y = a·f(b(x−h)) + k (combining shift, scale, reflection).

104
Q

In y = f(x) + k, how does k affect the graph?

A

It shifts the graph vertically: up by k if k>0, down if k<0.

105
Q

In y = f(x−h), how does h affect the graph?

A

It shifts the graph horizontally: right by h if h>0, left if h<0.

106
Q

For a horizontal shift, is it always x−h in the argument if we move right by h?

A

Yes. Right shift: x−h with h>0. Left shift: x−(−h)=x+h.

107
Q

What does y = −f(x) do to the parent function’s graph?

A

Reflects it across the x-axis.

108
Q

What does y = f(−x) do to the parent function’s graph?

A

Reflects it across the y-axis.

109
Q

Define a vertical stretch by factor a>1.

A

y = a·f(x), multiplies all y-values by a (makes the graph ‘taller’).

110
Q

Define a vertical compression by factor 0 < a < 1.

A

y = a·f(x), reduces all y-values, making the graph ‘flatter’.

111
Q

How is a horizontal compression by factor b>1 expressed?

A

y = f(bx), compresses along x-axis by 1/b.

112
Q

Write the formula for shifting a function f(x) up 4 units.

A

y = f(x) + 4.

113
Q

Write the formula for shifting a function g(x) down 2 units.

A

y = g(x) − 2.

114
Q

Write the formula for shifting h(x) right 7 units.

A

y = h(x−7).

115
Q

Write the formula for shifting p(x) left 5 units.

A

y = p(x + 5).

116
Q

Explain how the domain changes when shifting horizontally by h.

A

Domain’s x-values shift by −h, but the shape remains the same. If original domain is D, new domain is D shifted by h.

117
Q

If you have y=f(x)+k, does the domain change from the original function f(x)?

A

No. Vertical shifts do not affect x-values or domain.

118
Q

In y = (x−3)² + 4, what transformations from y=x² are present?

A

Right shift by 3, and up shift by 4.

119
Q

If a function’s domain was x≥0, then we apply x→x−2 shift, what is the new domain?

A

x−2≥0 → x≥2.

120
Q

If y=f(x) is known, how do we shift it left by 2 and down by 3 simultaneously?

A

y = f(x+2) − 3.

121
Q

Give a single transformation formula for shifting a function f(x) up k units and right h units.

A

y = f(x−h) + k.

122
Q

What is the formula for reflection across the x-axis of y=f(x)?

A

y = −f(x).

123
Q

What is the formula for reflection across the y-axis of y=f(x)?

A

y = f(−x).

124
Q

Which reflection changes sign of y-values: x-axis or y-axis reflection?

A

x-axis reflection changes y-values’ signs.

125
Q

Which reflection changes sign of x-values in the function argument?

A

y-axis reflection uses f(−x).

126
Q

How do you reflect across y=k (a horizontal line)?

A

First shift the function so line y=k becomes x-axis, reflect, then shift back: y=k−(f(x)−k).

127
Q

How do you reflect across x=h (a vertical line)?

A

Replace x with 2h−x. So y = f(2h−x).

128
Q

Is reflection across y=x the same as inverse function?

A

Yes, graphically it’s reflection over y=x, but it only forms an inverse if f is one-to-one.

129
Q

How do you reflect f(x)=√x across y-axis?

A

Use y=f(−x)=√(−x). But domain changes to x≤0.

130
Q

Give the transformation form for reflecting across x-axis and shifting up k.

A

y = −f(x) + k.

131
Q

If y=f(x) has domain x≥−1, after reflection across x-axis, does domain change?

A

No, reflection across x-axis doesn’t affect x, so domain remains x≥−1.

132
Q

Write a function that vertically stretches f(x) by factor 3.

A

g(x) = 3f(x).

133
Q

Write a function that vertically compresses f(x) by factor ½.

A

g(x) = ½f(x).

134
Q

If y=f(x) is multiplied by a factor a<0, is that also a reflection?

A

Yes. a negative factor includes reflection across x-axis plus vertical stretch/compression.

135
Q

Compare the transformation y=2f(x) vs. y=f(2x) in plain English.

A

y=2f(x) is vertical stretch by factor 2; y=f(2x) is horizontal compression by factor 1/2.

136
Q

Which formula changes outputs to half their size: y=0.5f(x) or y=f(0.5x)?

A

y=0.5f(x) compresses vertically by ½.

137
Q

If f(x)≥0 for x≥0, then 3f(x)≥?

A

≥0 as well, scaled up 3 times but no sign change.

138
Q

In a vertical stretch by factor a>1, does domain or range expand?

A

Range is stretched, domain is unaffected.

139
Q

What if y=−2f(x)? Summarize the transformations.

A

Reflection across x-axis, then vertical stretch by factor 2.

140
Q

If parent function is y=|x|, what is y=3|x| doing?

A

Vertical stretch by factor 3.

141
Q

If y=f(x) passes (2,4), where does y=4f(x) pass for x=2?

A

At (2,16).

142
Q

Write a function for horizontally stretching f(x) by factor 2.

A

g(x)=f(x/2) (the inside is x/2 for a 2× horizontal stretch).

143
Q

Write a function for horizontally compressing f(x) by factor ½.

A

g(x)=f(x/(1/2))=f(2x).

144
Q

Which transformation is y=f(3x)?

A

A horizontal compression by factor 1/3.

145
Q

If f(x)=x², then g(x)=f(2x) means g(x)=(2x)²=4x². Which transformation is that?

A

Horizontal compression by factor ½, but it looks like a vertical stretch by 4 in the equation.

146
Q

If h>1, what does y=f(hx) do?

A

Horizontal compression by factor 1/h.

147
Q

If 0<h<1, what does y=f(hx) do?

A

Horizontal stretch by factor 1/h (which is >1).

148
Q

Does y=f(bx) for b>0 change the domain set for real x?

A

No, but the function’s features appear ‘compressed or stretched’ horizontally.

149
Q

If y=f(½x), how is the graph changed from y=f(x) at x=4?

A

We evaluate f(2), so the features shift to the right (it’s a stretch factor 2).

150
Q

General formula for a horizontal scale factor k>0 is y=f((1/k)x). True or false?

A

True. If k>1, that’s a stretch; if 0<k<1, a compression.

151
Q

In a horizontal stretch by factor 3, a point at x=2 moves to x=6 or x=2/3?

A

It moves to x=6 (the function that was at 2 is now at 6).

152
Q

What is the general form combining shift, scale, reflection?

A

y = a·f(b(x−h)) + k.

153
Q

In y=a·f(b(x−h))+k, define each parameter’s effect: a, b, h, k.

A

a=vertical scale ± reflection, b=horizontal scale ± reflection, h=horizontal shift, k=vertical shift.

154
Q

Which transformations are done first, horizontal shifts or horizontal scalings?

A

Inside the parentheses: do scaling b then shift h. But practically we rewrite carefully to see the effect.

155
Q

Which transformations are done after you handle the x-changes (like b(x−h))?

A

Outside transformations: vertical scaling by a, then vertical shift by k.

156
Q

If we have y=−3f(2(x−1))+5, list transformations in order.

A

1) Shift right 1, 2) Horizontal compression by factor 1/2, 3) Reflect across x-axis, 4) Vertical stretch by 3, 5) Shift up 5.

157
Q

Sometimes we combine reflection across y-axis if b<0 in f(bx). True?

A

Yes. If b<0, there’s also a reflection across the y-axis.

158
Q

If a<0 in a·f(…), do we also have reflection across x-axis?

A

Yes, negative a includes reflection across x-axis plus scale factor |a|.

159
Q

Give the domain shift for y=f(b(x−h)) if b>0.

A

Shift to x≥h if original domain was x≥0, then compress or stretch by factor 1/b along x.

160
Q

For y=a·f(b(x−h))+k, how does the range shift if originally it was [m,∞) for f?

A

Scaled by factor a, reflected if a<0, then shifted up by k.

161
Q

Explain how to rewrite y=a·f(b(x−h))+k if we want to see horizontal shift more clearly.

A

Inside: b(x−h) = b·x − b·h, so shift is h = (b·h)/b but we have to be mindful that dividing or factoring out b.

162
Q

Define g(x)=−2f(3x+6). Which transformations are inside the parentheses?

A

3x+6 → factor out 3: 3(x+2). So horizontal shift left 2, then horizontal compression factor 1/3.

163
Q

Continuing that example, what do −2 and +1 do?

A

−2 is reflection across x-axis plus vertical stretch by factor 2, +1 is shift up by 1.

164
Q

If f(0)=2, what is g(0) for g(x)=2f(x)? Summarize the result.

A

g(0)=2×f(0)=2×2=4; vertical scale factor 2 at x=0.

165
Q

In y = f(2x−4), we can factor out 2: y = f[2(x−2)]. Summarize transformations.

A

Shift right 2, then horizontal compression factor 1/2.

166
Q

If we see y = f(−(x−3)), that is f(−x+3). Summarize transformations.

A

Shift right 3, reflect across y-axis, depending on sign inside. Actually it’s f(3−x), so it’s shift left 3? Carefully analyze.

167
Q

Wait, f(−(x−3))=f(−x+3). That means x is replaced by (3−x). So is that a reflection across x=1.5 or simpler?

A

Yes, rewriting might help. But typically we see it as reflection across y-axis if we fix the expression. We must be precise.

168
Q

Key tip: always isolate (x−h) by factoring out b. Then interpret sign for reflection. Good idea?

A

Yes. Factoring out the coefficient of x is the best approach.

169
Q

If the inside coefficient of x is negative, we get reflection across the y-axis plus possible shift. T/F?

170
Q

If the outside coefficient is negative, we get reflection across the x-axis. T/F?

171
Q

In practice, is it best to handle horizontal transformations first or vertical transformations first?

A

Typically handle inside (horizontal) transformations first, then the outside (vertical).

172
Q

When we do a horizontal shift x→(x−h), how does domain shift?

A

All x-values shift by +h. If domain was D, new domain is {x | x−h ∈ D}.

173
Q

When we do a vertical shift up k, how does range shift?

A

All y-values shift up by k. If range was R, new range is R+k.

174
Q

When we reflect across x-axis, how does range change if originally it was [m,∞)?

A

New range becomes (−∞, −m].

175
Q

When we reflect across y-axis, does range necessarily change from the original?

A

No, reflection across y-axis affects domain (x) not range (y).

176
Q

A horizontal scale factor by 1/2 (i.e. y=f(2x)) might do what to domain if the original domain was x≥0?

A

Now x≥0 is mapped to x≥0 still, but features occur twice as fast.

177
Q

Vertical stretch by factor a>1 modifies range how?

A

All outputs are multiplied by a, so if range was [m,n], new range is [am, an] (assuming no reflection).

178
Q

If a<0 in a vertical scale, e.g. −3, then there’s also reflection. True?

A

Yes, so the range flips sign plus scaling by 3.

179
Q

If domain was (−∞, 5] for f(x), and we shift right 2, what’s new domain for g(x)=f(x−2)?

A

(−∞, 7].

180
Q

If the range was all real y≥−1, after up shift by 3, it becomes y≥ what?

181
Q

If the range was all real y≥1, after reflection across x-axis, it becomes y≤ −1. T/F?

182
Q

What is the recommended step to handle y = 2f(−(x+1)) − 3 first?

A

Rewrite inside: −(x+1)=−x−1, factor out negative, etc. Then interpret reflection, shift, scale step by step.

183
Q

In transformations, is the order of horizontal transformations critical?

A

Yes, the order in which we apply shift vs. scale matters inside the argument.

184
Q

Which is typically done first in y=f(b(x−h)) if we read left to right in the argument?

A

First shift x→(x−h), then scale x→b(x−h).

185
Q

Can we do a combined transformation as x→b(x−h) in one step if we’re comfortable with factoring b out?

A

Yes, but carefully to avoid sign mistakes.

186
Q

If we see y=−f(2(x+1))+4, list transformations in a clear sequence.

A

1) Shift left 1, 2) Horizontal compression by factor 1/2, 3) Reflect across x-axis, 4) Vertical shift up 4.

187
Q

If the function is y=x² originally, how do we get y=−(x−3)²+2 in transformations?

A

Shift right 3, reflect across x-axis, shift up 2.

188
Q

If we want to compress horizontally by factor 1/3 and shift up 5 from y=x³, how do we write that?

A

y = x³ becomes y=f(3x)+5 or y=(3x)³+5 = 27x³+5 if f(x)=x³.

189
Q

Are transformations generally commutative (i.e. does shifting then reflecting yield same as reflecting then shifting)?

A

Not always, we must follow the correct order or rewrite carefully.

190
Q

If we do y=|2x| vs. y=2|x|, which is a horizontal vs vertical change?

A

y=|2x| is horizontal compression by 1/2. y=2|x| is vertical stretch by 2.

191
Q

List the transformations in y=2f(3x−6)−4, in correct order.

A

1) Shift right 2 (since 3(x−2)), 2) Horizontal compression factor 1/3, 3) Vertical stretch factor 2, 4) Shift down 4.

192
Q

When f is piecewise, do transformations apply piecewise or overall?

A

They apply to each piece, adjusting intervals accordingly.

193
Q

If a function is periodic (like sine/cosine), does horizontal scaling change its period?

A

Yes. y=f(bx) changes period to original period / b.

194
Q

If f is odd, reflection across y-axis vs x-axis – do they produce the same or different shapes?

A

For an odd function, reflection across y-axis is the negative. But it’s not necessarily the same shape as reflection across x-axis. We must be cautious.

195
Q

‘To compress horizontally by factor k’ means points get closer by factor k or 1/k?

A

If the formula is y=f(kx), actual numerical factor is 1/k. So if k>1, that’s a compression.

196
Q

Why do we factor out the b from x−h to interpret horizontal transformations?

A

Because y=f(b(x−h)) is y=f[b(x−(h))], shifting is h units, not h/b. Factoring clarifies.

197
Q

In a function transformation, can reflection be combined with scaling into a single factor a < 0?

A

Yes, a negative factor handles reflection + scale.

198
Q

Are vertical transformations done after horizontal ones in standard function transformation approaches?

A

Yes. Typically we handle inside function transformations (horizontal) first, then outside (vertical).

199
Q

If a function has domain [0,∞), after y=f(x−2), the domain is [2,∞). Why?

A

Because x≥2 ensures x−2≥0 for the new function.

200
Q

If a function has range (−∞,10], and we do y=f(x)+5, new range is (−∞, 15]? T/F?

A

True, everything shifts up by 5.

201
Q

Final tip: to identify transformations, always rewrite y in the form y=a·f(b(x−h))+k. T/F?

A

True. That clarifies each parameter’s effect.

202
Q

Find f(3) if f(x) = 2x + 1.

A

f(3) = 2(3) + 1 = 7.

203
Q

If g(x) = x², compute g(−2).

A

g(−2) = (−2)² = 4.

204
Q

Let h(x) = 5 − x. Evaluate h(7).

A

h(7) = 5 − 7 = −2.

205
Q

Find f(0) if f(x) = 3x² + 4.

A

f(0) = 3(0)² + 4 = 4.

206
Q

If j(x) = x + 1, what is j(j(2))?

A

First j(2)=2+1=3; then j(3)=3+1=4.

207
Q

For k(x)=|x|, evaluate k(−5).

208
Q

If p(x)=x−3, solve p(x)=0.

A

x−3=0 → x=3.

209
Q

Given r(x)=4−2x, find r(2) + r(−2).

A

r(2)=4−2(2)=0; r(−2)=4−2(−2)=4+4=8; sum=0+8=8.

210
Q

If m(x)=2x+5, compute m(4)−m(1).

A

m(4)=2(4)+5=13; m(1)=2(1)+5=7; difference=13−7=6.

211
Q

For f(x)=x²−1, find f(2)+f(−2).

A

f(2)=2²−1=4−1=3; f(−2)=4−1=3; sum=3+3=6.

212
Q

If f(x)=x+2, for which x does f(x)=0?

A

x+2=0 → x=−2.

213
Q

If g(x)=2x−3, solve g(x)=1.

A

2x−3=1 → 2x=4 → x=2.

214
Q

Evaluate f(−1) if f(x)=3−x².

A

f(−1)=3−(−1)²=3−1=2.

215
Q

Find h(2) if h(x)=3x+5 for x≥2. No domain issue, so h(2)=?

A

h(2)=3(2)+5=6+5=11.

216
Q

If j(x)=−x, compute j(5).

A

j(5)=−5.

217
Q

If k(x)=2, a constant function, find k(10).

218
Q

For r(x)=x³, find r(−3).

A

r(−3)=−27.

219
Q

Given p(x)=4−x, find p(0).

A

p(0)=4−0=4.

220
Q

Compute q(1)+q(2) if q(x)=2x.

A

q(1)=2; q(2)=4; sum=6.

221
Q

If f(x)=5x−1, for which x is f(x)=9?

A

5x−1=9 → 5x=10 → x=2.

222
Q

If f(x)=x², compute f(3)−f(2).

A

f(3)=9; f(2)=4; difference=5.

223
Q

Find domain & range for g(x)=|x| if no restrictions otherwise.

A

Domain: all real x. Range: [0,∞).

224
Q

Evaluate h(1)+h(−1) if h(x)=x²+1.

A

h(1)=1+1=2; h(−1)=1+1=2; sum=4.

225
Q

For j(x)=4−x², find j(0).

A

j(0)=4−0=4.

226
Q

If m(x)=3x−4, find m(3) and m(−1).

A

m(3)=3(3)−4=9−4=5; m(−1)=3(−1)−4=−3−4=−7.

227
Q

Compute p(2) for p(x)=2x+3.

A

p(2)=2(2)+3=7.

228
Q

If f(x)=x−2, find x if f(x)=5.

A

x−2=5 → x=7.

229
Q

For r(x)=−2x, evaluate r(−4).

A

r(−4)=−2(−4)=8.

230
Q

If s(x)=x²+1, find s(1) & s(−1).

A

s(1)=2; s(−1)=2.

231
Q

If f(x)=2x+5, find f(0)+f(−2).

A

f(0)=5; f(−2)=2(−2)+5=1; sum=6.

232
Q

Let h(x)=2−x. For x=4, h(4)=?

A

2−4=−2.

233
Q

If k(x)=3−2x, solve k(x)=0.

A

3−2x=0 → 2x=3 → x=1.5.

234
Q

If j(x)=x+1, find j(0).

235
Q

Compute f(1)+f(2)+f(3) if f(x)=x.

236
Q

If g(x)=x²−4, find g(2).

A

2²−4=4−4=0.

237
Q

For p(x)=−x, compute p(5). Then sum p(5)+p(−5).

A

p(5)=−5; p(−5)=5; sum=0.

238
Q

If q(x)=1−2x, find x if q(x)=−3.

A

1−2x=−3 → −2x=−4 → x=2.

239
Q

Let f(x)=x². Evaluate f(−1)+f(−2).

A

f(−1)=1; f(−2)=4; sum=5.

240
Q

For r(x)=2x−1, find r(1), r(2), r(3).

A

r(1)=1; r(2)=3; r(3)=5.

241
Q

If t(x)=|x−3|, evaluate t(3).

A

|3−3|=0.

242
Q

If u(x)=x²−1, find u(1).

A

1²−1=0.

243
Q

If h(x)=|x|−2, compute h(−2).

A

|−2|−2=2−2=0.

244
Q

Let k(x)=3x. Solve k(x)=9.

A

3x=9 → x=3.

245
Q

For a constant function c(x)=7, find c(−100).

246
Q

If g(x)=x−4, evaluate g(5)+g(−1).

A

g(5)=1; g(−1)=−5; sum=−4.

247
Q

If f(x)=2−x², find f(2).

A

2−(2²)=2−4=−2.

248
Q

For p(x)=4|x|, compute p(−3).

A

4|−3|=12.

249
Q

If q(x)=x+2, find x for which q(x)=0.

A

x+2=0 → x=−2.

250
Q

Compute r(2)+r(3) for r(x)=2x−5.

A

r(2)=−1; r(3)=1; sum=0.

251
Q

If t(x)=−x+10, solve t(x)=4.

A

−x+10=4 → −x=−6 → x=6.