View Single Post
Old Mar 17, 2009 | 02:51 PM
  #37  
Red X's Avatar
Red X
x pǝɹ
 
Joined: Feb 2003
Posts: 6,246
Likes: 1
From: Upstate
Default

Originally Posted by cpvdh
i just googled "ln derivative" and went to the first few hits

wathworld is legit, lots of good stuff there, mathtopia sp? was good i think
i havent done anything with math for a few years now so im a bit out of the loop

i used to try to use university web pages alot though, classes with notes online are super useful, and questions are pretty universal if you know what i mean :rick:
I think he knows how to compute the ln derivative, I just don't think he knows how to break it up.

Originally Posted by F22B Prelude
y = ln(x^4+5x^2)^3/2

y' = ((1/x^4+5x^2)(4x^3+10x))^3/2

= 3/2(4x^3+10x/x^4+5x^2)

You just didn't use the chain rule right, see above post

edit: verified with my calculator (sort of). My calc minimized it a lil bit but it looks to be similar.
Reply