it is actually integrate from 0 to -infin, but I understand that part. When I see xe^x I integrate it and get (1/2x^2)(e^x). My solutions manuel says it is (x-1)(e^x). I don't get the same answer when using my work, what am I doing wrong?
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it is actually integrate from 0 to -infin, but I understand that part. When I see xe^x I integrate it and get (1/2x^2)(e^x). My solutions manuel says it is (x-1)(e^x). I don't get the same answer when using my work, what am I doing wrong?
Integrate by parts:.
Here you setand so
and
.
Hence, as they say, the result.
So how does (xe^x)-(e^x) become (x-1)e^x? I'm sure I'm missing some simple rule here...
Yes:
(xe^x)-(e^x)
= xe^x - e^x
= e^x(x - 1)
= (x - 1)e^x