Question

could someone please help me im trying to get this final review done and im sick and tired.
a. find the period and amplitude of the cosine function.
b. at what values of theta for 0 <= theta <= 2pi do the maximum value(s), minimum value(s) and zeros occur?

Answer 1

It's really hard to see your graph. The amplitude is the y distance from y=0 to the peak of the wave form. It looks to me like the amplitude is 2.

The period will be the distance on the x axis from 0 to the next peak of positive( y=2). It looks like pi/2

The max values are the peaks in the positive y direction. So it looks like 0, pi/2, pi, 3pi/2, 2pi

The minimum values are the peaks in the negative y direction. So it looks like pi/4, 3pi/4, 5pi/4, 7pi/4

The zero are where the cosine wave crosses the x axis. So it looks pi/8, 3pi/8, 5pi/8, 7pi/8, 9pi/8, 11pi/8,13pi/8,15p/8