algebra precalculus - $\cos(\arcsin(x)) = \sqrt{1 - x^2}$. How? - Mathematics Stack Exch
How does that bit work? How is $$\cos(\arcsin(x)) = \sin(\arccos(x)) = \sqrt{1 - x^2}$$ ... @RestlessC0bra We draw a right triangle because that's kind of how sine and cosine are defined in the first place (or at least, that's the defi...