Question

Use the graph below to answer the question that follows:

trig graph with points at 0, 0 and pi over 2, negative 4 and pi, 0 and 3 pi over 2, 4 and 2 pi, 0 and 5 pi over 2, negative 4 and 3 pi, 0

What trigonometric function represents the graph? (6 points)
a. f(x) = 4 sin(x − pi over 2 )
b. f(x) = −4 sin(x − pi over 2 )
c. f(x) = 4 cos(x − pi over 2 )
d. f(x) = −4 cos(x − pi over 2 )

Answer 1

d. f(x) = -4 cos(x - π/2)

Explanation:

Answer 2

The points correspond to those of a vertically stretched cosine function that has been shifted π/2 to the right and reflected across the x-axis. The appropriate choice is

d. f(x) = -4 cos(x - π/2)