Practice Scaling Functions in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Scaling a function multiplies its output by a constant (vertical scaling) or compresses/stretches its input (horizontal scaling), changing amplitude or period without changing the shape.

Vertical scaling stretches or squishes the graph up/down; horizontal scaling stretches or squishes it left/right. Both change the function's measurements without altering its fundamental character.

Showing a random 20 of 50 problems.

Example 1

challenge
The graph of f(x)=x2 is to be transformed so it has the SAME graph whether you apply f(2x) or cf(x). Find c.

Example 2

easy
For f(x)=x2, write 5f(x) explicitly.

Example 3

medium
A sine wave y=sin⁡x has period 2π. Write the function with period π (and unchanged amplitude).

Example 4

medium
If f(x) has the point (6,9), where does it map under f(13x) (horizontal scaling)?

Example 5

challenge
Find a single constant a so that a⋅f(x) sends the point (3,8) of f to (3,−2). Then state what happens to the x-intercepts.

Example 6

medium
Does the transformation f(x)→f(−x) change the y-values of points on the graph?

Example 7

hard
For f(x)=ex, show that f(x+ln⁡5)=5f(x), illustrating that for exponentials horizontal shifts equal vertical scalings.

Example 8

medium
For f(x)=∣x∣, write the function obtained by vertical compression by factor 14 and reflection across the x-axis.

Example 9

medium
Write the function that vertically compresses f(x)=4x2 by a factor of 14, and identify its leading coefficient.

Example 10

challenge
A wave is modeled by y=Asin⁡(Bx). Starting from sin⁡x, find A and B so the amplitude is 5 and the period is 2π3.

Example 11

hard
Starting from f(x)=cos⁡x, find a and b in g(x)=acos⁡(bx) so that g has amplitude 2.5 and frequency 3 (i.e., 3 cycles per 2π).

Example 12

easy
Write the function that vertically reflects f(x)=x2+1.

Example 13

medium
f(x) has a zero at x=−2. What is the zero of f(14x)?

Example 14

hard
If g(x)=cf(x) shares all of f's x-intercepts, what can c be?

Example 15

challenge
Find a single g(x)=af(bx) that simultaneously sends f's point (6,4) to (2,12) for some function f. State a and b.

Example 16

easy
If f(x) has a y-intercept at (0,7), where is the y-intercept of 12f(x)?

Example 17

easy
Describe how g(x)=3f(x) and h(x)=12f(x) transform the graph of f(x)=x. Evaluate both at x=4.

Example 18

easy
Describe the transformation from f(x) to 3f(x).

Example 19

easy
For f(x)=x2, write 2f(x) explicitly.

Example 20

medium
A model C(x) gives cost for x items. To express cost when each input unit represents a dozen items, you use C(12x). Is this horizontal stretch or compression, and by what factor?