Question

Integral help

Answer 1

uhh why aren's x^2 and x combined?

Answer 2

How to do this
\[\large \int \frac{cos(x)}{x+1}dx\]

Answer 3

integration by parts is the only way

Answer 4

let u = x+1

and dv = cosx

Answer 5

I try parts and I don't get a solution

Answer 6

It's same

Answer 7

let me try

du = dx
v = sin x

so we have \[\large (x+1)\cos x - \int \sin x dx\]
right?

Answer 8

oh wait lol. sorry wrong first term

Answer 9

\[\large (x+1)\sin x - \int \sin x \;\rm dx\]

Answer 10

that seems integrable

Answer 11

No. You have \[(x+1)^{-1}\] no?

Answer 12

@xlegendx You need to make u=1/(x+1) in this case

Answer 13

oh so that's why i got something integrable

Answer 14

it shouldn'r be...at least not on an elementary level...darn i have lost my touch in integration...anyway...this doesn't have a simple solution

Answer 15

http://www.wolframalpha.com/input/?i=int+%28cosx%29%2F%28x%2B1%29 <--he says it has some imaginary parts

Answer 16

Is not cosine some imaginary exponent solution?