Question

A bike tire has a diameter of 14 inches. It runs over a piece of gum that sticks to the tire. Write a cosine function that describes the height of the gum above the ground as a function of angular distance.
a. y = -7 cos x + 7


b. y = 7 cos x + 14


c. y = -7 cos x + 14


d. y = 14 cos x + 28

Answer 1

Answer:

  a.  y = -7cos(x) +7

Step-by-step explanation:

The middle level of the gum is 7 inches above the ground, and it oscillates 7 inches either side of that. Thus the offset of the cosine function (average height) is 7 and the multiplier (amplitude of oscillation) is also 7. The -7 on the cosine multiplier means the height of the gum is zero at x=0.