Practice Function Families in Math

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

Quick Recap

A function family is a group of functions sharing the same general form and behavior, differing only in the values of one or more parameters.

y=mx+by = mx + b is a family of lines. Different mm and bb give different lines.

Showing a random 20 of 50 problems.

Example 1

medium
Two parabolas are y=x2y = x^2 and y=โˆ’2x2y = -2x^2. Name their shared family and two ways the parameter changes the graph.

Example 2

hard
Classify y=eโˆ’x2y = e^{-x^2} โ€” is it linear, polynomial, exponential, or something else?

Example 3

challenge
A family is defined by f(x)=ax2f(x) = a x^2 with aโ‰ 0a \ne 0. Prove that every member passes through the origin and explain why varying aa cannot change that.

Example 4

easy
In y=ax2+bx+cy = a x^2 + b x + c, what role does aa play (besides being a parameter)?

Example 5

medium
A table shows f(1)=2f(1)=2, f(2)=5f(2)=5, f(3)=10f(3)=10, f(4)=17f(4)=17. Identify the family.

Example 6

medium
What family is y=x3y = \sqrt[3]{x} (cube root)?

Example 7

hard
A linear and an exponential function both pass through (0,5)(0, 5) and (1,10)(1, 10). Find each. At x=4x = 4, which is larger?

Example 8

challenge
A mystery function has these values: f(1)=2f(1) = 2, f(2)=6f(2) = 6, f(3)=18f(3) = 18, f(4)=54f(4) = 54. Identify the family and the specific member.

Example 9

hard
For the family y=asinโก(bx)+cy = a \sin(bx) + c, which parameter changes the vertical midline?

Example 10

hard
The family y=xny=x^n for integer nโ‰ฅ1n\geq1 has different behavior depending on whether nn is even or odd. Classify and explain the symmetry of y=x2y=x^2, y=x3y=x^3, y=x4y=x^4, y=x5y=x^5.

Example 11

medium
Classify y=4xy = 4^x versus y=x4y = x^4 by family, and state which grows faster for large xx.

Example 12

medium
The family y=kxy = \frac{k}{x} (with kโ‰ 0k \neq 0). Describe the role of kk on the graph.

Example 13

medium
Which family does y=5sinโก(2x)y = 5\sin(2x) belong to?

Example 14

medium
Two members of the linear family pass through given points: line A has slope 2, line B has slope 2 but a different intercept. What is true about their graphs?

Example 15

easy
Is y=1xy = \frac{1}{x} in the same family as y=x2y = x^2?

Example 16

easy
Classify y=โˆ’4x+1y = -4x + 1 by family.

Example 17

medium
A function doubles every time xx increases by 1, and equals 5 at x=0x = 0. Identify its family and write the specific member.

Example 18

easy
In the family y=a(xโˆ’h)2+ky = a(x - h)^2 + k, which parameter shifts the vertex horizontally?

Example 19

hard
A radioactive sample has half-life 55 years. Identify the family and write a model starting from 8080 g.

Example 20

medium
A line and a parabola both pass through (0,0)(0, 0) and (2,4)(2, 4). Identify each by family.