Solve ∫ cos(x) dx = sin(x) + C

Step-by-step solution

1. Recall: $\frac{d}{dx}\sin x = \cos x$.

2. So $\sin x$ is an antiderivative of $\cos x$.

3. Therefore $\int \cos x \, dx = \sin x + C$.

4. Note: integral of $\cos$ is $+\sin$ (positive); contrast with integral of $\sin$, which is $-\cos$ (negative).