I had a brain fart and for some reason I can't remember how to do this simple derivative.

y = ln (x^2 + 5)

If I remember correctly, isn't the derivative:

2x/(x^2 + 5)

9/4/2008 7:15:59 PM

yep

9/4/2008 7:41:04 PM

just remember this

y = ln [f(x)]

y' = f'(x)/f(x)

9/7/2008 8:04:33 PM

yeah. the chain rule

There isn't a lot of applications of the derivative of ln (x) in the level of calculus that I teach my students so I had forgotten how to actually find the derivative.

9/7/2008 8:28:11 PM

if i only had to learn the math that i had applications for, i could've had a much more enjoyable freshman year.

9/7/2008 8:38:35 PM