Question

Choose the function whose graph is given by: (attached photo)

Answer 1

The correct answer is y = 2cos(3x)

Answer 2

Answer:

2cos(3x)

Step-by-step explanation:

If the function were just cos(x), then the second peak would happen at 2π.  Instead though, it happen 2π / 3.   That means that the coefficient of x must be 3.

At zero, we see a peak of the curve, so we're dealing with a cos function, that peak happens at (0, 2), so the coefficient of the function is 2.

That tells us that the function graphed here must be 2cos(3x).