# [SOLVED] Integration by parts help...

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• Feb 1st 2010, 12:01 AM
stickyMATH
[SOLVED] Integration by parts help...
Can someone please help me with this problem I am stuck! (Headbang)

$
\int 3arctan(2x)dx
$

My first step has been:
dv = 3 dx
v= 3x
u = arctan(2x)
du = [1/(1+4x^2)]*2

Giving me...
$
3xarctan(2x) - \int 3x*[1/(1+4x^2)]*2dx$

Thanks!!!!! (Rock)
• Feb 1st 2010, 12:03 AM
mr fantastic
Quote:

Originally Posted by stickyMATH
Can someone please help me with this problem I am stuck! (Headbang)

$
\int 3arctan(2x)dx
$

My first step has been:
dv = 3 dx
v= 3x
u = arctan(2x)
du = [1/(1+4x^2)]*2

Giving me...
$
3xarctan(2x) - \int 3x*[1/(1+4x^2)]*2dx$

Thanks!!!!! (Rock)

To solve the new integral substitute $w = 1 + 4x^2$.
• Feb 1st 2010, 12:12 AM
stickyMATH
Ahhhh I was not going that direction! Thanks!