How do you prove the identity #sec^2(x)-tan^2(x)=1#?
1 Answer
Sep 24, 2015
Use the facts that
#sec(x) = 1/cos(x)color(white)("XXX")tan(x) = sin(x)/cos(x)#
and
#1 -sin^2(x) = cos^2(x)#
Explanation:
#=1/cos^2(x) - sin^2(x)/(cos^2(x))#
#=(1 -sin^2(x))/cos^2(x)#
#=cos^2(x)/cos^2(x)#
#=1#
