Question

How do you simplify `sin(90 + x)`?

Answer 1

`sin (90 + x) = cos x`

Explanation:

`sin (90 + x) = cos x`

Method 1: Using plots of `sin x` and `cos x`. A shift of -90 degrees of `sin x` gives you `cos x`

Method 2: `sin (A +- B) = sin A cos B +- cos A sin B`