Question

HELP PLEASE?
find the indefinite integral. ∫ cos 6x dx

Answer 1

Most people do that by substitution, however I'd recommend you to get used to several guess methods considering such integrals.

Because I am pretty sure you know how to integrate:
\[\Large \int\cos(x)dx \]

Answer 2

@Spacelimbus okay

Answer 3

So you can guess that :\[\Large \int \cos(6x)dx\approx \sin(6x)+C \]

But that's not quite correct yet is it? Apply the chain rule and you'll see that you get an unwanted 6 infront of the cos(6x) term. So, you only need to fix that.

Answer 4

okay thanks (:

Answer 5

@Spacelimbus so it would be