Question

Anybody know the answer?

Answer 1

I think it should end up to be cos + cos

Answer 2

That equation would become :

[cosx*cosx +sinx*sinx], [cos^2(x)+sin^2(x)]

When adding the squares of a sin and cos, the answer is one. The is a trig identity you MUST memorize.

So : cos^2(x)+sin^2(x)=1