simple differentiation i can't get (1 Viewer)

[YBK]

hey.. argg! something's up with me!

Differentiate:
ln(tanx)


I know the answer is sec^2x/tanx but don't know how they got it...

can someone please explain how for me? thanks

 

[YBK]

I got it!
w00t!

tanx is on the bottom cause it's a log function, and derive tanx on the top which is sec^2

therefore sec^2x/tanx is the answer!

w00t! wow, considering we've done integration in 4u and it took me that long to remember is worrying... :S

 

[shimmerz_777]

for any log function,
d/dx of log f(x) will = f'(x)/f(x) remember that and it shouldnt b hard