Integration by parts problem: integral of e^x(sin[3x])dx

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Opus89

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I am working on this integral:

integral of e^x(sin[3x])dx

You have to integrate by parts a couple of times and I finally got an answer of e^x(-3cos3x + sin3x) divided by 10. I plugged this integral into an integral calculator and it gave me -1/10 * e^x(3cos3x -sin3x). Is this the same thing? I'm having a hard time seeing how the calculator did the algebra and got the negatives where it did. Is the answer i got correct? Thanks
 
Opus89 said:
I am working on this integral: integral of e^x(sin[3x])dx. You have to integrate by parts a couple of times and I finally got an answer of e^x(-3cos3x + sin3x) divided by 10. I plugged this integral into an integral calculator and it gave me -1/10 * e^x(3cos3x -sin3x). Is this the same thing? I'm having a hard time seeing how the calculator did the algebra and got the negatives where it did. Is the answer i got correct? Thanks
Click to expand...

Multiply out your answer and "simplify" it - do the same to the answer from the calculator - then compare.
 
I see that If I were to multiply out the -1/10 that the calculator got, it would turn in to what I have. Or so it appears to me. It seems to be the same thing to me.
 
Thanks for the help Khan. That was awfully simple now that I look at it. :oops: :oops:
 
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