Calculus help

[E.C.]

okay so im doing integration by parts and i just dont get it

the question is integrate x^7 ln(3x) dx

u= ln(3x)

du= 1/x dx

v= (x^8)/8

dv= x^7 dx

can someone help?

 

[chardi]

i'm so glad i don't have to take math anymore. good luck with that dude

 

[Grodent87]

deriv of ln(3x) is 3/x

 

[Grodent87]

shit nevermind no its not

 

[E.C.]

its the anitderiv. 3x/3

 

[E.C.]

3/3x woops

 

[chicken]

integrate by parts you can just plug into a formula. it's weird because substitution is so much like the chain rule, but by parts is totally new.

anyways i would solve it for you but wolfram can show you the steps better anyways...

http://www.wolframalpha.com/input/?i=integrate+x^7+ln%283x%29+dx

 

[E.C.]

i know the answer i jsut dont understand how to get to it

 

[chicken]

did you click "show steps?"

it pretty clearly shows the formula, the variables to choose, and then it all plugged in.

 

[NOSNOWJUSTICE]

I should be studying. But I'd rather to math. Weird?

Hope it helps...

 

[NOSNOWJUSTICE]

DAMN THAT'S COOL!

Just finished my Calc 1, 2, and 3 series yesterday. Wish I knew of that... hahaha

damn....

 

[chicken]

yeah sometimes it does not show the steps that well. Super useful for so many things once you learn how to type it all in right.

plus it does other crazy stuff, this is the weather when i was born....

http://www.wolframalpha.com/input/?i=weather+january+9+1990+durban+south+africa

 

[Style+eeze]

Haha, I took AP Calc AB last year. I'm pretty glad I chose to take AP Stat instead of BC this year...