integrating..

• October 11th 2008, 04:11 PM
hashi
integrating..
Hi,

how do you go about integrating this:

sin(t)*cos(n*t) with respect to t?

Thanks
• October 11th 2008, 04:58 PM
Nacho
$
\sin (x)\cos (y) = \frac{{\sin \left( {x - y} \right) + \sin \left( {x + y} \right)}}
{2}
$

can you continue?
• October 11th 2008, 04:59 PM
RedBarchetta
Well, assuming n is a constant, then use this rule to split the integral up into something more manageable.

$
\sin (mx)\cos (nx) = \frac{1}
{2}\left[ {\sin (m - n)x + \sin (m + n)x} \right]
$

Let m=1 and n=n. (Cool)
• October 11th 2008, 05:19 PM
hashi
thank you guys.. i can do it now!

:D