Practice Test

Question 6 • Precalculus

Which graph represents the function y is equal to cosine of 4 x ?

Answer

Image with description On a coordinate plane, a function has a maximum at 1 and minimum at negative 1. It completes one period at pi. It crosses the y-axis at (0, 0).

Image with description On a coordinate plane, a function has a maximum at 1 and minimum at negative 1. It completes one period at StartFraction pi Over 2 EndFraction. It crosses the y-axis at (0, 0).

Image with description On a coordinate plane, a function has a maximum at 1 and minimum at negative 1. It completes one period at StartFraction pi Over 2 EndFraction. It crosses the y-axis at (0, 1).

Image with description On a coordinate plane, a function has a maximum at 1 and minimum at negative 1. It completes one period at pi. It crosses the y-axis at (0, 1).

Explanation

The cosine function has a maximum of 1 and a minimum of −1. For y = cos(4x), the period is 2π ÷ 4 = π/2, and at x = 0 the value is cos(0) = 1. So the graph with period π/2 that crosses the y-axis at (0, 1) is choice C.

AI-written and checked against the verified answer.

More from this Course

Practice Test

Practice Test

Practice Test