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OpenStudy (anonymous):
I just did an integral and i'm trying to simplify my final answer:
xln(2x+1)-x+(1/2)(ln(2x+1))+C
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OpenStudy (mr.math):
Is it \(x\ln(2x+1)-x+\frac{1}{2}\ln(2x+1)+C?\)
OpenStudy (anonymous):
yes
OpenStudy (mr.math):
I would recommend that you take \(\ln(2x+1)\) as a common factor.
OpenStudy (mr.math):
Could you tell me what the original integral was?
OpenStudy (anonymous):
the problem is that the answer is \[(1/2)(2x+1)\ln(2x+1)-x+C\]
What happened to the x in xln(2x+1)
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OpenStudy (anonymous):
The original integral was [int_ln(2x+1)dx]
OpenStudy (anonymous):
i set u=ln(2x+1) and dv=dx
OpenStudy (mr.math):
Your answer is right then. Here how they did it:
\[x\ln(2x+1)+\frac{1}{2}\ln(2x+1)-x+C=(x+\frac{1}{2})\ln(2x+1)-x+C\]
OpenStudy (mr.math):
But if you take \(\frac{1}{2}\) as a common factor from the first parentheses, you get
\[\frac{1}{2}(2x+1)\ln (2x+1)-x+C\]
OpenStudy (anonymous):
I see. So you multiply by 2 within the parenthesis and divide by 2 to make up for the difference
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OpenStudy (mr.math):
Exactly!
OpenStudy (anonymous):
Ur awesome. Thanks again my friend
OpenStudy (mr.math):
You learn fast by the way :)
OpenStudy (anonymous):
I disagree...but I'll take the compliment
OpenStudy (mr.math):
You have to :P
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