Question

Integration Question. See below

Answer 1

Where is the question?

Answer 2

\[\int\limits \cos^3 \theta d \theta\]

Answer 3

Sorry it took me a few minutes to write it lol

Answer 4

is this cos^3?

Answer 5

yes it is

Answer 6

you write it as cos^2 cos and then you let u = cos. we solved the same one in class. All the best.

Answer 7

The idea of separating the integrand into cos^2(theta)*cos(theta) is correct, just a correction, let u=sin(theta)

Answer 8

Ok thank you I will give it a go

Answer 9

\[\Large \int\limits\limits \cos^3 \theta d \theta = \int\limits\limits \cos^2 \theta \cos \theta d \theta = \]\[\Large \int\limits\limits (1-\sin^2 \theta) \cos \theta d \theta = \] \[\Large \int\limits\ \left[ \cos \theta -\sin^2 \theta \cos \theta \right]d \theta =\]
\[\Large \int\limits\ \cos \theta d \theta - \int\limits \sin^2 \theta \cos \theta d \theta =\]

Left one is an easy integral, use the u=sin theta on the right.

Answer 10

Thanks, that makes much more sense now :)
I wasn't sure where to use the u = sin theta