2010-04-07, 09:11 PM
To further append on, I'd like to take the general case for
![[Image: ye7bq7l.png]](http://mathurl.com/ye7bq7l.png)
Usually, one put this into three different cases: When m is odd, when m is even and n odd, and when m and n are even.
For the first case, m is odd. We can thus represent m = 2k + 1. Remembering the identity
![[Image: ydw92ux.png]](http://mathurl.com/ydw92ux.png)
we obtain the following:
![[Image: yzp7y9q.png]](http://mathurl.com/yzp7y9q.png)
Then we just combine the single sin with dx, and set sin x dx = -d(cos x)
For the second case, use the exact same way. Just swap cos and sin, and set cos x dx = d * sin x
For the third case, we'll should use another identity:
![[Image: ybl8s3f.png]](http://mathurl.com/ybl8s3f.png)
Then, just substitute this in, and there you go.
Noah
![[Image: ye7bq7l.png]](http://mathurl.com/ye7bq7l.png)
Usually, one put this into three different cases: When m is odd, when m is even and n odd, and when m and n are even.
For the first case, m is odd. We can thus represent m = 2k + 1. Remembering the identity
![[Image: ydw92ux.png]](http://mathurl.com/ydw92ux.png)
we obtain the following:
![[Image: yzp7y9q.png]](http://mathurl.com/yzp7y9q.png)
Then we just combine the single sin with dx, and set sin x dx = -d(cos x)
For the second case, use the exact same way. Just swap cos and sin, and set cos x dx = d * sin x
For the third case, we'll should use another identity:
![[Image: ybl8s3f.png]](http://mathurl.com/ybl8s3f.png)
Then, just substitute this in, and there you go.
Noah

