Thread: Help proving trig identities.

(tan x)(1-cot x)
Here's what I tried:
Sin/cos(1-cos/sin)
--That obviously didn't work


cos x/1-sin x=sec x + tan x
I don't really know how to begin on this one.


Any hints and help is appreciated. Thanks in advance.

Originally Posted by beetz

(tan x)(1-cot x)
Here's what I tried:
Sin/cos(1-cos/sin)
--That obviously didn't work

of course it didn't work, there's no identity here! what should you be proving?

cos x/1-sin x=sec x + tan x

Consider the LHS.

multiply through by and simplify

and use parentheses next time to clarify what you mean. you should have typed (cos x)/(1 - sin x). here it was easy to see what you meant, but it won't always be