1. Indefinite integral

integral 3sin4xdx=?
Thanks.

2. Originally Posted by nystudent2729
integral 3sin4xdx=?
Thanks.
lets take this slow.

$\int 3 \sin 4x~dx$

Let $u = 4x$

$\Rightarrow du = 4~dx$

$\Rightarrow \frac 14 ~du = dx$

So our integral becomes

$\frac 14 \int 3 \sin u~du = \frac 34 \int \sin u~du$

can you finish? do you remember what the integral of sine is?