im not sure where or how you managed to get y = 1.2. If you are looking for x intercepts, y will always be 0. If you need to find where the function intercepts the x axis, you need to set the entire function equal to 0. Afterwards you will notice that sin (function) = 0, and where is sin (some number) = 0? Sin (0) = 0. When you solve this for your equation, you will get the first intercept. But sin is repeating, with a period of 2pi. Sin is 0 at every multiple of pi. If you set your function equal to the first 3 multiples of pi, 0 1 2, you will find the answers.
Your function being the contents inside of sin
Along with the number at the end.
Edit: I'm on my phone and just realized your equation has a shift at the end. You will need to do something similar to what I said but not exactly. :p
Use sin^-1