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Differential equations w/ trig

  • Thread starter b200w
  • Start date
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?
 
1,341
3
1/sec(x) = cos(x) -- does that help?
 
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!
 
1,341
3
Yeah the integration looks right.
 

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