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)=x2f(x) = x^2 is to be transformed so it has the SAME graph whether you apply f(2x)f(2x) or cf(x)cf(x). Find cc.

Example 2

easy
For f(x)=x2f(x) = x^2, write 5f(x)5 f(x) explicitly.

Example 3

medium
A sine wave y=sinโกxy = \sin x has period 2ฯ€2\pi. Write the function with period ฯ€\pi (and unchanged amplitude).

Example 4

medium
If f(x)f(x) has the point (6,9)(6, 9), where does it map under f(13x)f\left(\tfrac{1}{3}x\right) (horizontal scaling)?

Example 5

challenge
Find a single constant aa so that aโ‹…f(x)a \cdot f(x) sends the point (3,8)(3, 8) of ff to (3,โˆ’2)(3, -2). Then state what happens to the x-intercepts.

Example 6

medium
Does the transformation f(x)โ†’f(โˆ’x)f(x) \to f(-x) change the y-values of points on the graph?

Example 7

hard
For f(x)=exf(x) = e^x, show that f(x+lnโก5)=5f(x)f(x + \ln 5) = 5 f(x), illustrating that for exponentials horizontal shifts equal vertical scalings.

Example 8

medium
For f(x)=โˆฃxโˆฃf(x) = |x|, write the function obtained by vertical compression by factor 14\tfrac{1}{4} and reflection across the xx-axis.

Example 9

medium
Write the function that vertically compresses f(x)=4x2f(x) = 4x^2 by a factor of 14\tfrac14, and identify its leading coefficient.

Example 10

challenge
A wave is modeled by y=Asinโก(Bx)y = A\sin(Bx). Starting from sinโกx\sin x, find AA and BB so the amplitude is 5 and the period is 2ฯ€3\frac{2\pi}{3}.

Example 11

hard
Starting from f(x)=cosโกxf(x) = \cos x, find aa and bb in g(x)=acosโก(bx)g(x) = a \cos(b x) so that gg has amplitude 2.52.5 and frequency 33 (i.e., 33 cycles per 2ฯ€2\pi).

Example 12

easy
Write the function that vertically reflects f(x)=x2+1f(x) = x^2 + 1.

Example 13

medium
f(x)f(x) has a zero at x=โˆ’2x = -2. What is the zero of f(14x)f(\tfrac{1}{4} x)?

Example 14

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

Example 15

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

Example 16

easy
If f(x)f(x) has a y-intercept at (0,7)(0, 7), where is the y-intercept of 12f(x)\tfrac{1}{2} f(x)?

Example 17

easy
Describe how g(x)=3f(x)g(x)=3f(x) and h(x)=12f(x)h(x)=\frac{1}{2}f(x) transform the graph of f(x)=xf(x)=\sqrt{x}. Evaluate both at x=4x=4.

Example 18

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

Example 19

easy
For f(x)=x2f(x) = x^2, write 2f(x)2f(x) explicitly.

Example 20

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