The inverse is the symmetrical function relatively to the function y=x. So, it basically means, that to find the inverse, you just need: 1. Switch x and y (or f(x)): x = 5H(x) + 2 2. Solve for y again (or for f(x)): 5H(x) = x -2 H(x) = (x-2)/5 This is the inverse.
Hmmm if you don't have a Unit Circle, this is a good time to get one, many you can find online. Anyhow, check your unit circle for cos(30°) and sin(30°).
