Posted by eddie on .
prove the identity
sec^2x times cot x minus cot x = tan x

trig 
Reiny,
LS = (1/cos^2 x)(cosx/sinx)  cosx/sinx
= 1/(cosxsinx)  cosx/sinx
= (1  cos^2x)/(sinxcosx)
= sin^2x/(sinxcox)
= sinx/cosx
= tanx
= RS