1. ## derivative

Hi everyone...

Could someone help me find the derivative of ln(2cosx) ? So far, I have
(1/2cosx)(-2sinx), so (-2sinx/2cosx). Is this right???

I would appreciate all the help I can get!

2. Hi

Yes, it's correct. Get rid off the two 2 and give your answer using $\tan x$ and it'd be perfect.

3. ## Is it negative?

Oh, thank you! Would it be -tanx?

4. Originally Posted by Foxtenn5
Hi everyone...

Could someone help me find the derivative of ln(2cosx) ? So far, I have
(1/2cosx)(-2sinx), so (-2sinx/2cosx). Is this right???

I would appreciate all the help I can get!
Yes, you have solved the problem correctly. Alternatively, you could break up the expression to $\ln{2} + \ln{(\cos x)}$ and then differentiate. Either way, the 2 isn't going to change the result of $-\tan {x}$.