There is more than one possible solution here that I can see.

I'm happy to help but we need to focus on the one you require. First thing to do is draw a sine function that goes through these 2 points.

I have one in mind. It has the y-intercept at (0,4) and half way through the cycle returns to (2,4). Can you draw a picture of that?

If so what is the period of the function?