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# integration by parts Watch

1. Use integration by parts to integrate t *lnt with limits t=k and t=1

I did
u=ln t
du/dt = 1.t
dv/dt = t
v=1

so [lnt *1] - integrate 1 *(1/t) dt
then insert in limits t=k and t=1

but it didn't come to the answer of (1/2k^2) * lnk - 1/4k^2 + 1/4

the question also says k is positive.
2. (Original post by 0utdoorz)
dv/dt = t
v=1
This is not correct.
3. (Original post by 0utdoorz)
Use integration by parts to integrate t *lnt with limits t=k and t=1

I did
u=ln t
du/dt = 1.t
dv/dt = t
v=1

so [lnt *1] - integrate 1 *(1/t) dt
then insert in limits t=k and t=1

but it didn't come to the answer of (1/2k^2) * lnk - 1/4k^2 + 1/4

the question also says k is positive.

For

4. (Original post by notnek)
Looking at the lines that follow, I'm thinking that error was a typo.
I edited my post to address the main issue

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