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How do I solve this integral (c4)

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Reply 1
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the bear
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what methods have you tried ?
Reply 2
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rambo1168
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Original post by the bear
what methods have you tried ?



Integration by parts, I thought id make u=sin^2t and dv/dx= cost


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Reply 3
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the bear
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Original post by rambo1168
Integration by parts, I thought id make u=sin^2t and dv/dx= cost


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the simplest method is substitution ( change of variable )
Reply 4
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rambo1168
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Original post by the bear
the simplest method is substitution ( change of variable )


Make u=sint?


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Reply 5
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the bear
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Original post by rambo1168


try it and see
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melmarbi
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Reply 7
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rambo1168
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Original post by the bear
try it and see


I tried :frown: I give up


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Reply 8
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rambo1168
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Original post by melmarbi


I don't understand how you got sin^3t/3


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Reply 9
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the bear
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Original post by rambo1168
I don't understand how you got sin^3t/3


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they were able to see the "reverse derivatve".

if you persevere with the substitution you should arrive at the same answer.
Original post by rambo1168


Let Sint = t

You'll get a t^2 to integrate...this is the simplest method....


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(edited 10 years ago)
Reply 11
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melmarbi
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rambo1168
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I got stuck on the bit circled


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Reply 13
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melmarbi
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Original post by rambo1168
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I got stuck on the bit circled


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Actually inside the integral you should have written also cost which then would be erased and you will end up only with u^2 du and then it is easy

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