I was hoping for some help finding the inverse of the function:

$\displaystyle h(x)=cos^2x+2cosx+1$

I am stuck at the point where I have:

$\displaystyle y-1=(cosx)(cosx)+cosx+cosx$

I was hoping to find a way to combine the cosine terms, so that I can just take the arc-cosine of both sides and be done, but can't figure out how.