Question

What is the period of y = 2cos(3x - 2pi)?
A: 3pi
B: 6pi
C: 3pi - 2
D: 2pi/3

Answer 1

The answer is D: 2pi/3

Answer 2

The correct option is D.

Explanation:

The given function is

`y=2\cos (3x-2\pi)` .... (1)

The general form of cosine function is

`y=A\cos (Bx-C)+D` ... (2)

Where, A is amlitude, 2π/B is period, C is phase shift and D is midline.

From equation (1) and (2), we get

`B=3`

The period of the function is

`period=(2\pi)/(B)=(2\pi)/(3)`

Therefore the correct option is D.