No that's not correct try using the reduction formula.
What is the integral cos^{6}(x)? I just want to make sure I am correct.
The answer I got was [(3sin(4x) + 2sin(2x) + 5x)/16] + C
but I have no clue if I am correct and am not very confident in my integration skills.
If your answer is different, it'd be a great help if you could show me the process you took to get there.
Thanks!
No I don't think it is correct because the derivative of [(3sin(4x) + 2sin(2x) + 5x)/16] + C
is not equal to cos6(x) . Moreover you didn't show to us how you did it...
Anyway use repeated integration by parts and you will get it...but be patient because the process is lengthy...
Good Luck
SMAD - I don't think the reduction formula is within the scope of my course, so if this question comes up in my exam I don't think I will get marks for process.
Do you know of another way to do it?
MINOANIMAN- Yeah, I thought so, My working took more than a page (possibly because of my relatively large handwriting) so I didn't post that sorry, but I broke up the cos^6(x) into (cos^2(x))^3 and substituted the half angle formula (cos^2(x) = 1/2(1+cos(2x)) and went from there, but I may have made some algebraic errors that I can't see... :\ I'm just wondering if there's a better way to break it up that will result in less possible errors.
Thanks for your help!