Choose the function whose graph is given by: (attached photo) y= 2cos(3x)
y= -2cos(3x)
y= 2cos(pi/2 x)
y= 2cos(1/3 x)

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).

ian gone lie this got me confused

step-by-step explanation: