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: Definite Integral of a Trig Fxn

  1. Sep 28, 2012 #1
    ∫tan^5 x sec x

    I want to split the tan^5 x into a (sec^2 x - 1) but I only have sec x. So I'm a bit stuck. Help is appreciated.
  2. jcsd
  3. Sep 28, 2012 #2


    User Avatar
    Homework Helper

    Bring the integral in the form ∫f(cos(x))sin(x)dx.

  4. Sep 28, 2012 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Finding the anti-derivative of tan5(x) sec(x) is a lot like solving your previous tread.

    Split tan5(x) into tan4(x) tan(x) then use the trig identity which will change tan4(x)  into a combination of secant functions.
  5. Sep 29, 2012 #4
    ^ That did the trick. Thank you : D
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook