It looks like the base graph of sinx, so we will start from there. The range of the y value goes from -1 to 5 which is a distance of 6. The amplitude is half of that, so the amplitude is 3.
So we now have y = 3sinx.
But we see that (0,2) is a point on the graph, so it is shifted 2 units up, which gives us a final equation of:
y = 3sinx + 2
