Families by Graph Features
Function Equations (name the family)
Function Transformations
Function Family Clues
Evaluate the function
100

This function family's graphs repeat themselves over a constant cycle. They are wavy shaped.

Trigonometric Functions

100

f(x)= -2x + 4

LINEAR

100

Parent function: y = x

Graph moved up 3 and got twice as steep

What is the new equation?>

y = 2x + 3

100

Functions in this family have a variable in the exponent.

Exponential functions

100

f(x) = 4x - 6

Evaluate for x = 4 

f(4) = 10

200

This function family's graphs make a smooth curve. They change direction and have a minimum or a maximum. The rate of change is not constant.

QUADRATIC

200

f(x)=|8x-2|-3

ABSOLUTE VALUE

200

Parent function: y = sin x

Graph moved down 2 and the waves are now 4 high

What is the new equation?

y = 4 sin x - 2

200
You can use right triangles OR the unit circle to find these functions for different angles.
Trigonometric Functions
200

g(x)= 3|x+2|

Evaluate for x = -5

g(-5) = 9

300

The graphs in this function family change direction (increasing/decreasing), and they are made of two straight lines. They have a minimum or a maximum.

ABSOLUTE VALUE

300

A(t)=2,000(1.02)t

EXPONENTIAL

300
Parent function: y = x2

The graph moved left 3, got twice as wide, and moved down 2... What is the new equation?

y= 1/2(x+3)- 2

300

These functions are the inverse functions of exponential functions.

Logarithmic Functions

300

f(x)= log2x

Evaluate for x = 32

f(32) = 5

400

This function family's graphs has a smooth curve and   a domain of (0, + infinity) 

They either increase or decrease only and do not change direction, and the rate of change increases or decreases.

EXPONENTIAL

400

g(x)= (x+2)(x-3)

QUADRATIC  (in factored form)

400
Transformed function is y = 2(x-3)

The parent function was 2x

How did the graph change from the original function? Describe the transformation 

It moved right 3

400

These equations have a root over the variable

Radical Functions

400

h(x) = (x-2)/(x+2)(x-3)

Evaluate for x = -3

h(x)= undefined!!  (can't divide by zero)

500

This function family graph has vertical and horizontal asymptotes and its end behavior is 

as x --> + infinity, f(x) --> + and - infinity

as x --> - infinity, f(x) --> + and - infinity

RATIONAL FUNCTIONS

500
f(x) = (x+3)(x-4)(x+2)(x+1)2

POLYNOMIAL  

(Bonus: what degree is it?)

500

The new function is

f(x)= -20 cos (x) +3

How did it change from the original function, y=cos x?

It flipped upside down, the amplitude is now 20 (so the waves are 20 from midline to top/bottom, and the midline is 3

500

The equation is in the form 

anxn+a(n-1)x(n-1)+a(n-2)x(n-2)+ . . .a0

Polynomial Functions (with degree n)

500

f(x) = 3x+2 - 7

Evaluate for x = 2

f(2) = 74

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