Help with an integral please

  • #1
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Homework Statement


This is one of these AP free response questions divided into a,b,c,d,etc. but im just going to ask for a small part of the problem.

I need to integrate y=7tecost






The Attempt at a Solution



I tried using U substitution but it didn't work. I tried things like the following:

Integrate with respect to t (dt).

make ecost=u and t=-cosln(t)



but it seems I am complicating my life. Any tips?
 

Answers and Replies

  • #2
LCKurtz
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I would feel very safe telling you there is no elementary antiderivative for that function. My best guess would be it was supposed to be$$
\int (7\sin t) e^{\cos t}\, dt$$which would be straightforward.
 
  • #3
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I would feel very safe telling you there is no elementary antiderivative for that function. My best guess would be it was supposed to be$$
\int (7\sin t) e^{\cos t}\, dt$$which would be straightforward.

Yeah, I researched a bit around and for some reason this can only be done with a calculator (definite integral).

Wonder how the computer/calculator does it actually.


This was from the 2010 AP Calculus AB test
 
  • #4
LCKurtz
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Yeah, I researched a bit around and for some reason this can only be done with a calculator (definite integral).

Wonder how the computer/calculator does it actually.


This was from the 2010 AP Calculus AB test

Well, your original post did not give a definite integral. That opens the door to numerical routines such as Trapezoidal or Simpson's rules.
 

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