Chapter 1 Flashcards
X in a function
one and only one Y
Y in a function
as many x’s as it wants
In a fraction
The denominator cannot equal 0
In a radical
The radical is > or = to 0
Fun formula
f(x+h) - f(x)/h
h cannot equal 0
Increasing interval
where the graph is going up
Decreasing intervals
where the graph is going down
[]
including number
()
excluding number
Even
f(-x) = f(x)
Odd
f(-x) = -f(x)
Parent functions
search check
Vertical shifts
outside of function
Horizontal shifts
inside of function
Reflection across x-axis
outside of function
Reflection across y-axis
inside of function
Vertical stretch
□f(x)
Vertical compression
1/□f(x)
Horizontal stretch
f(□x)
Horizontal compression
f(1/□x)
Absolute value
makes any negative parts of a function positive (y values positive, not x)
(f + g)(x) =
= f(x) + g(x)
(f-g)(x) =
= f(x) - g(x), g(x) can’t be 0
(fg)(x) =
= f(x) x g(x)
(f/g)(x) =
= f(x)/g(x)
(f º g)(x) =
= f(g(x))
(g º f)(x) =
= g(f(x))
To find a composites domain:
first consider the rules of the inside function, then the entire function
When dividing inequalities by a negative:
the sign flips
How to know if a function has an inverse:
- one-to-one ratio
- passes VLT and HLT
- switch every (x, y)
- symmetry around y=x axis
- f(g(x)) = g(f(x)) = x
radicals:
plus or minus
When writing a function, if anything is in front of x:
Factor it:
(3-x) + 2 -> (-(x + 3)) + 2
(xa)b
xab
xa ÷ x
xa - b
xa x xb
xa + b
(xy)a
xaya
(x/y)a
xa ÷ ya
x0
1
x-a
1/xa
xa/b
b√xa