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
