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: How to integrate (sec x)^4, help please

  1. Jan 2, 2006 #1
    May i know how to integrate (sec x)^4 ??

    the answer is tan x + 1/3 (tan x)^3
     
  2. jcsd
  3. Jan 2, 2006 #2

    Pyrrhus

    User Avatar
    Homework Helper

    Try writing your integral as
    [tex] \int (\tan^{2} x + 1) \sec^{2} x dx [/tex]
     
  4. Jan 2, 2006 #3
    okok.......thanx
     
  5. Jan 2, 2006 #4
    try using [tex]u=tg(x)[/tex]
    [tex]du=\frac{dx}{cos^2(x)}[/tex]
    and [tex]\frac{1}{cos^2(x)}=1+tg^2(x)=1+u^2[/tex]
     
    Last edited: Jan 2, 2006
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook