Question

Which function's graph has a period of 2?

(functions attached below)

I think it is B. y=-4sin pi x

Please explain. Thank you!

Answer 1

so the only choices that have are b. and c. so how do I pick between them two?

Answer 2

Given
y = Asin (Bx) or y = A cos (Bx)

period = 2Pi / B

Answer 3

so B works :)