How do you integrate ∫cos3(3x)dx?
1 Answer
Mar 9, 2017
Explanation:
This can be a tricky one, first we need to find a way to express the function to remove the power of 3.
To do this, we can try:
Use
Finally we can use:
=
Of course, the cosine function has even symmetry so:
Which will give us the exression:
So it will naturally follow that:
Which easily integrates to give:
