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Integration by parts watch

1. The question asks me to find

Im not quite sure which bit to set as the derivative, because if i set the derivative to then i have to integrate sec^20 which i dont know how to do . If i tried it the other way which is to set the derivative to theta, but then it doesnt solve anything because i end up with an even more complicated integrand. Please help! rep for help.
2. Can't read it? Says 'unparseable or potentially dangerous latex formula'.
3. Without being able to read the question, sec^2 is something you should know how to integrate (by recognizing it as the derivative of something).
4. can't really help till we can see the function to integrate
5. (Original post by Clarity Incognito)
Can't read it? Says 'unparseable or potentially dangerous latex formula'.
Alright can you read it now?
6. (Original post by jdude22)
The question asks me to find

Im not quite sure which bit to set as the derivative, because if i set the derivative to then i have to integrate sec^20 which i dont know how to do . If i tried it the other way which is to set the derivative to theta, but then it doesnt solve anything because i end up with an even more complicated integrand. Please help! rep for help.
Wolframalpha (click show steps):

http://www.wolframalpha.com/input/?i...e+x+sec^2+x+dx

enjoy!
7. (Original post by jdude22)
The question asks me to find

Im not quite sure which bit to set as the derivative, because if i set the derivative to then i have to integrate sec^20 which i dont know how to do . If i tried it the other way which is to set the derivative to theta, but then it doesnt solve anything because i end up with an even more complicated integrand. Please help! rep for help.
Yeah follow Dfranklin's advice, think about what the integral of sec^2theta or conversely, what do you differentiate to get sec^2theta?
8. (Original post by jdude22)
The question asks me to find

Im not quite sure which bit to set as the derivative, because if i set the derivative to then i have to integrate sec^20 which i dont know how to do . If i tried it the other way which is to set the derivative to theta, but then it doesnt solve anything because i end up with an even more complicated integrand. Please help! rep for help.
If you integrate sec^2 theta you'd get tan theta. So then differentiate theta.
9. well label u as theta v' as sec^2theta and then follow it through btw, sec^2theta integrates to tantheta
10. (Original post by FinalFlash)
If you integrate sec^2 theta you'd get tan theta. So then differentiate theta.
Thanks, + rep

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