Evaluate the integral sinx/cos^2x dx from 0 to pi/3.

So I've gotten it to tanxcosx, but I don't know the indefinite integral of these, and I couldn't find it in my book. Can anyone help?

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- August 11th 2010, 12:07 PMbobsanchezIntegration with trig functions
Evaluate the integral sinx/cos^2x dx from 0 to pi/3.

So I've gotten it to tanxcosx, but I don't know the indefinite integral of these, and I couldn't find it in my book. Can anyone help? - August 11th 2010, 12:13 PMyeKciM
- August 11th 2010, 12:14 PMPlato
- August 11th 2010, 12:26 PMbobsanchez
Ah okay, let me work the problem. Thanks.

- August 11th 2010, 12:28 PMbobsanchez
-1?

- August 11th 2010, 12:31 PMyeKciM
i got result 1 :D

- August 11th 2010, 12:39 PMbobsanchez
-1/cos(60) = -2

-1/cos(0) = -1

-2 - (-1) = -2 + 1 = -1

Did I mess up somewhere in there or enter it wrong? - August 11th 2010, 12:44 PMTheCoffeeMachine
Let to get Plato's result (without the typo minus).

- August 11th 2010, 12:46 PMyeKciM
- August 11th 2010, 05:33 PMbobsanchez
Evaluate the integral sec2xtan2x dx.

sec2x + C

This is another good one. My first try resulted in sec2x + C, but was wrong. - August 11th 2010, 05:40 PMProve It
- August 11th 2010, 09:19 PMbobsanchez
- August 11th 2010, 09:25 PMeumyang
- August 11th 2010, 09:35 PMbobsanchez
...wow...forgot the chain rule? Really? *sigh*

Anyways, thanks for the help. Alright, so...I just integrate and multiply it by du, correct? So (1/2)sec2x + C? - August 11th 2010, 09:38 PMeumyang
I could read that as , but I know that's not what you meant.