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Need some help integrating please

  1. Aug 2, 2010 #1
    hey guys im absolutely stumped on this one integration problem:

    it asks us to integrate sin (2x) e ^ (sin x)

    i integrated by parts once and was left with an even larger term to integrate, which leads me to believe that i might be doing it wrong

    any help is appreciated, thanks
  2. jcsd
  3. Aug 2, 2010 #2
    Try expanding sin(2x) using a double angle formula.
  4. Aug 2, 2010 #3
    wow ok i feel like an idiot. when i split it into double angles i had (2 sin cos e^sin) and i kept having my two terms for integration by parts being (cos sin) and (e ^ sin) instead of the VERY OBVIOUS one which i kept missing which was (sin) and (cos e ^sin) which gave a very nice and smooth integration

    thanks again
  5. Aug 2, 2010 #4
    You could also have done a substitution u = sin x.
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