SOLUTION: Derive the formula of derivatives with the angle"x" of the trigonometic fuction using the 4-step differention process. cos(x)

Before you can prove that, you must first prove two other theorems.

 

and



I will assume you have already proved those.  If you haven't, post again,
asking for those proofs.











Since we are assuming the two theorems at the top, the expression 

 

approaches 0, and the expression

 

approaches 1, so the expression approaches



which is



Edwin