Let f(x)=4lnabsolutevalue(sec(x)+tan(x))

Question

zepdrix · Answer

Oh this is a fun one :) lol

anonymous · Answer

f'=secx

cruffo · Answer

$$ \large f(x) = 4\ln\vert\sec(x) + \tan(x)\vert$$

anonymous · Answer

this is a formula !!

zepdrix · Answer

Yah but he probably needs to do the work mah... -_-

anonymous · Answer

4 sec x

cruffo · Answer

He/she hasn't said what they want to do with it :)

zepdrix · Answer

Hmmmmm true :) Find f'(x)? What's up AJ? :D

anonymous · Answer

Actually it gets even more fun it is find f"(x)

zepdrix · Answer

Are you allowed to use the shortcut that mahmit posted? Or do you need to show all the steps?
(This is a derivative that eventually you'll just memorize, that's why i ask)

anonymous · Answer

it was obvious what he/she wanted !!

anonymous · Answer

I need to show the steps unfortunately :(

anonymous · Answer

lu)'=u'/u

anonymous · Answer

4secxtanx+sec2x/secx+tanx=4secx

anonymous · Answer

I thought that the derivative sec(x)tan(x) not sec(x)+tan(x) equaled sec(x)

zepdrix · Answer

(secx)'=secx(tanx)

Yes that is true, that's where we'll be heading after we find the first derivative.
The first derivative unfortunately will give us something rather sloppy, and we'll have to do a little work to simplify it down.

zepdrix · Answer

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