- #1
MysticDude
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Homework Statement
Okay so today I started to learn about integration by parts and I understand the basics of it and can do some of the simpler problems, but this one made me stop.
I have to integrate ln(x).
I know the answer is xln(x) - x but I have to prove it.
Homework Equations
[tex]\int u dv = uv - \int v du[/tex]
The Attempt at a Solution
Okay so what I do is make a table and list my u,du,v,dv. Here is my table:
u = ln(x); v = 1(because ln(x) = 1*ln(x))
du = 1/x; dv = 0;
Okay so the start is ln(x) instead of xln(x) so that's not a good first step. And the [tex]\int vdu[/tex] part is equal to 1[tex](x(\frac{1}{x}) = 1)[/tex]. At this part I'm stuck. I mean I could change the table for the start to be xln(x) but that doesn't make sense to me because where the x come from? I checked Wolfram Alpha but the steps confused me for this problem.
I'll appreciate any help!
:D