I'm studying for my finals and I have this integral that I'm trying to evaluate (part of a bigger problem):
$\int\sqrt{150^2-x^2} \cdot dx$
I have evaluated a few integrals of this type before so the first thought that came to my mind was to substitute $x = \sin t$ and $dx = \cos t \cdot dt$.
So now I have:
$\int \sqrt{150^2-\sin^2t} \cdot \cos t \cdot dt$
However, here is where I'm getting stuck. Usually instead of having $150^2$ I have $1$, and by using $1-\sin^2t = \cos^2t \space$ I can continue, but not in this case.
How should I go on?