MATH SOLVE

3 months ago

Q:
# HELP, Prove: (tan(x)+sec(x))^2=2sec^2x+2tansec(x)-1

Accepted Solution

A:

Expand the left side:[tex](\tan x+\sec x)^2=\tan^2x+2\tan x\sec x+\sec^2x[/tex]The Pythagorean identity tells us[tex]\tan^2x+1=\sec^2x[/tex]so we get[tex](\tan x+\sec x)^2=(\sec^2x-1)+2\tan x\sec x+\sec^2x=2\sec^2x+2\tan x\sec x-1[/tex]as needed.