Question

`sin(cos^-1(4/sqrt(p^2+16))) =` ?

Answer 1

`p/sqrt(p^2+16)`

Explanation:

`sin(arccos(a))= sqrt(1-a^2)`

then

`sin(cos^-1(4/sqrt(p^2+16))) = sqrt(1-16/(p^2+16)) = p/sqrt(p^2+16)`