Question

Can someone integrate this?:

(e^x)(cosx)

Answer 1

you need integration by parts

Answer 2

Oh this is a fun one XD

Answer 3

I've tried doing integration by parts - it just keeps me round and round in circles.

Answer 4

your absolutely right integration by parts is useless here

Answer 5

Yes you'll go round and round a couple times, then you'll end up with a piece on the end being the integral you started with, and you'll be able to do some algebra from there :)

Answer 6

integration by parts will only really work if the derivative of either e^x or cos(x) = 1

Answer 7

no parts will work :D it just takes a little extra work to finish off the problem.

Answer 8

show us please :)

Answer 9

Oh okay - I'll keep trying with parts. : ) But is that the only way to solve this question? Yes, I would also like to see how this could work.

Answer 10

integration by substitution aint gonna work either

Answer 11

I'll give you a random hint. If you ever end up with something like this:


integral (LOL) = a + b + c - integral(LOL)
and you keep going into a loop, you can change "integral (LOL)" into a temporary variable, (like Z).

So:

Z = a + b + c - Z

How would you "solve for Z"?

Answer 12

I may have missed a sign somewhere in there, i kinda rushed through it. It's probably right though.