Question

What is the period of y = 2cos(3x—2pi)
a.3pi
b.6pi
c.3pi-2
d.2pi/3​

Answer 1

d.2pi/3​

Explanation:

Suppose we have a cosine function in the following format:

`y = acos(bx + c)`

Only b is relevant to find the period.

The period is:
`P = (2\pi)/(|B|)`

In this question:

`y = 2cos(3x - 2\pi)`

Then B = 3.

`P = (2\pi)/(|B|) = (2\pi)/(|3|) = (2\pi)/(3)`

So the correct answer is:

d.2pi/3​