Question

$\int \left(\sin 5x+\sin 7x\right)dx$

Answer 1

Consider the given integral.

$I=\int (\sin 5x+\sin 7x)dx$

We know that

$\int \sin xdx=-\cos x+C$

Therefore,

$I=-\frac{\cos 5x}{5}-\frac{\cos 7x}{7}+C$

Hence, this is the answer.