Inverse trigonometric Functions,

Please can you explain to me this spot ? I understand the 1/cos conversion but yet again I dont get how it's done, if someone could explain to me step by step would be of a great help ! :)

http://screencast.com/t/ff70wSEEo4U

Question

Inverse trigonometric Functions,

Please can you explain to me this spot ? I understand the 1/cos conversion but yet again I dont get how it's done, if someone could explain to me step by step would be of a great help ! :)

http://screencast.com/t/ff70wSEEo4U

christos · Answer

@agent0smith @hartnn @ajprincess @amistre64 @dan815 @e.mccormick @ganeshie8 @goformit100 @hba @Hero @Luigi0210 @phi @RolyPoly @zzr0ck3r

hartnn · Answer

derivative of sec inverse x is standard, what did u not understand in that ?
do u need proof of derivative if sec inverse x ?

phi · Answer

This is one of those annoying ambiguities in math...

typically   $ x^{-1} = \frac{1}{x}$
but in this case $ \sec^{-1}(x) $ means the arc secant
the inverse secant

phi · Answer

in other words
$$ \sec^{-1}(x) ≠ \frac{1}{\cos(x)} $$

christos · Answer

Thanks guys !!

christos · Answer

There are just some things that are stupid yet again they confuse you !!

agent0smith · Answer

still need help @Christos ? looks like you got it sorted...