Answer
$-\frac{1}{3}cos 3x +C$
Work Step by Step
Put u = 3x.
Then $\frac{du}{dx}= 3$ or dx= du/3
Therefore $\int $sin 3x dx = $\int$ sin u $\frac{du}{3}$= $\frac{1}{3}\int$sin u du
= $\frac{1}{3}$(-cos u)+C= $-\frac{1}{3}$cos 3x +C
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.