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Integration by parts question

Colonel Sanders · 2007-07-03 12:18:38

haven't done this since LC!!! doing a loss distribution actuarial problem: trying to integrate x.b.exp(-bx) by parts. I set u = x and dv = b.exp(-bx) the answer I got was 1/b.exp(-bx)- x.exp(-bx) + c am I correct????

03-07-2007 12:18pm

#1

Colonel Sanders

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haven't done this since LC!!!

doing a loss distribution actuarial problem:

trying to integrate x.b.exp(-bx) by parts.

I set u = x

and dv = b.exp(-bx)

the answer I got was 1/b.exp(-bx)- x.exp(-bx) + c

am I correct????

0

Comments

#2 03-07-2007 12:38pm

Michael Collins

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Looks good to me apart from the sign of the first term should be negative...

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#3 03-07-2007 12:59pm

Colonel Sanders

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Re-did it, getting a different answer, very confused

arghhhhhhh!

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#4 03-07-2007 1:10pm

Colonel Sanders

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re did it and got your answer Michael, thanks!!!

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#5 06-07-2007 9:02pm

MathsManiac

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For future ref: you should never really be stumped trying to figure out if you've done an integral correctly; just differentiate your answer and see.:)

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