1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Integration of Trigonomic Functions

  1. Oct 4, 2011 #1
    I have come across the problem of ∫cos^(3)x by parts. I have no idea how to integrate this. I know that I need to change the way I write cos^(3)x and I have seen people put cosx(1-sinx).

    Please could you let me know where to find these equivilent ways of writing trigonomic formula? I assume there must be a table or something?

    Thanks,

    Andy

    PS Sorry if this isn't the clearest explanation.



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Oct 4, 2011 #2

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    I think you mean that cos3(x) = cos(x){1-sin2(x)} .

    That's because sin2(x) + cos2(x) = 1 .
     
  4. Oct 4, 2011 #3
    You're probably right. This is the problem I'm having, I don't know what the equivalent expressions are.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...