Question

Which equation represents the graph below?

Answer 1

y = cos(2x)

Explanation:

This is equation must be a cosine function because it starts at a nonzero number. We can conclude that the final answer is D because the amplitude is 1 not 2. Also, the period (2π/k) is equal to 2π/π = 2.

See the image below for the different parts of a cosine/sine function.

I hope this helps!