1. Not finding help here? Sign up for a free 30min 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!

Differential equations w/ trig

  1. Mar 18, 2009 #1
    Okay this is the second time writing this out, hopefully it won't log me out again...

    Given:
    dy/dx = (e^y * sin^2(x))/(y*sec(x))

    I separated out and integrated the y side using parts (for brevity's sake I won't repeat the math here as it's straightforward and presumably correct). I currently have this:

    -(y+1)/e^y = INT[ sin^2(x)/sec(x) dx ]

    My problem is I've never been able to completely grasp trig relations and I'm probably just missing something obvious but I spent an hour combing my book and previous homework assignments and I can't find a clue where to start. If someone could point me in the right direction I'll presumably be off and running. How would I integrate the RHS of the equation?
     
  2. jcsd
  3. Mar 18, 2009 #2
    1/sec(x) = cos(x) -- does that help?
     
  4. Mar 18, 2009 #3
    So substitution yields sin^3(x)/3 then? Now it's just a question of isolating y on the other side... wish me luck hahaha! Thanks!
     
  5. Mar 18, 2009 #4
    Yeah the integration looks right.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook