Module 1 Flashcards
A Function:
Is a mapping from a set of inputs to a set of outputs with exactly one output for each input
If no domain is stated for a function y = f(x):
the domain is considered to be the set of all real numbers x for which the function is defined.
When sketching the graph of a function f
Each vertical line may intersect the graph, at most, once
How many zeros and y-intercepts does a function have?
A function may have any number of zeros but it will only have one y-intercept.
To define the composition g∘f:
the range of f must be contained in the domain of g.
Even Functions
are symmetric about the y-axis
Odd functions
Are symmetric about the origin
Composition of two functions
(g∘f)(x) = g(f(x))
Absolute value function
f(x) = |x| = {x,x≥0
{x,x<0
composite function
given two functions f and g, a new function, denoted g∘f, such that (g∘f)(x) = g(f(x)).
decreasing on the interval I
a function decreasing on the interval I if, for all x1 ,x2 ∈ I, f(x1) ≥ f(x2) if x1 < x2.
dependent variable
the output variable for a function
domain
the set of inputs for a function
even function
a function is even if f(−x) = f(x) for all x in the domain of f.
graph of a function
the set of points (x, y) such that x is in the domain of f and y=f(x)
increasing on the interval I
a function increasing on the interval I if for all x1,x2∈I,f(x1)≤f(x2) if x1 < x2
independent variable
the input variable for a function
odd function
a function is odd if f(−x)=−f(x) for all x in the domain of f
range
the set of outputs for a function
symmetry about the origin
the graph of a function f is symmetric about the origin if (−x,−y) is on the graph of f whenever (x,y) is on the graph.
symmetry about the y-axis
the graph of a function f is symmetric about the y-axis if (−x,y) is on the graph of f whenever (x,y) is on the graph
table of values
a table containing a list of inputs and their corresponding outputs
vertical line test
given the graph of a function, every vertical line intersects the graph, at most, once
zeros of a function
when a real number x is a zero of a function f, f(x) = 0
The power function f(x)=x^n is an even function or an odd function if
if n is even and n≠0, and it is an odd function if n is odd
What is the Domain of the root function f(x) = x^1/n?
has the domain [0,∞) if n is even and the domain (−∞,∞)
if n is odd.
What is the domain of the rational function f(x)=p(x)/q(x), where p(x) and q(x) are polynomial functions?
It is the set of x such that q(x)≠0.
{ x| q(x)≠0}
A polynomial function f with degree n≥1
satisfies f(x)→±∞ as x→±∞. The sign of the output as x→∞ depends on the sign of the leading coefficient only and on whether n is even or odd.
What are some examples of transformations of functions?
Vertical and horizontal shifts, vertical and horizontal scalings, and reflections about the x– and y-axes
Point-slope equation of a line
y − y1 = m(x − x1)
Slope-intercept form of a line
y = mx+b
Standard form of a line
ax + by = c