math precalculus

Question

Which of the following has a period of 5?

y = sin(2πx/5)

none of these

y = sin5πx

y sin(πx/5)

Answer 1

y = sin(2πx/5) has period 5 because period T = 2π/(2π/5) = 5

Answer 2

The period of oscillation is found from b,π the coefficient of x: T = 2π/b. In the first case y = sin(2πx/5), T = 2π/(2π/5) = 5.