reduction integrate (1 Viewer)

shannonm

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Hi The question is
evaluate

/1
| ... x<sup>3</sup>e<sup>-x</sup> dx
/0






also the previous part of the question is to find the general formula:
I<sub>n</sub> = nI<sub>n-1</sub> - e<sup>-1</sup> (n>0)
which i could do ok, i just keep getting the wrong answer when trying to evaluate that integral
thanks
 
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:: ck ::

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this is not a reduction formula... i think either u have misinterpreted the question or u have typed it up wrong..

remember that e<sup>-1</sup> is a constant

u can take it out of the integral

thus integral [1 to 0] x^3 / e dx
= 1/e integral[1 to 0] x^3
= (1 / e) * [ (x^4 / 4) ]<sup>1</sup><sub>0</sub>

the rest u can do ..
 

Affinity

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it is a reduction formula quesiton.
and if you can do that .. it's probably the book's problem
 
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Rorix

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shannom edited it after ryan posted so it probably wasn't a reduction question initially...

yes that question is rather easy
 

:: ck ::

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Affinity said:
it is a reduction formula quesiton.
and if you can do that .. it's probably the book's problem
he edited it after...
 

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