Question

Determine the period of the following trigonometric function.
y=4cos(8πx)

Answer 1

The period of y = 4 cos(8πx) is 2π/(8π) = 1/4, since

cos(x - 2π) = cos(x)

and if we replace x with 8πx, we get

cos(8πx - 2π) = cos(8πx)

and

8πx - 2π = 8π (x - 1/4)