Primitive of Sine Function

Theorem

 * $$\int \sin \left({x}\right) dx = - \cos \left({x}\right) + C$$.

Proof
From Derivative of Cosine Function, we have $$\frac{d}{dx} \cos \left({x}\right) = -\sin \left({x}\right)$$.

The result follows from the definition of indefinite integral.