How do you prove sec2theta=sec^2theta/(2-sec^2theta)?

1 Answer
Aug 19, 2016

"To prove: "sec2theta=sec^2theta/(2-sec^2theta)

RHS=sec^2theta/(2-sec^2theta)

=(cos^2thetasec^2theta)/(cos^2theta(2-sec^2theta))

=1/(2cos^2theta-cos^2thetasec^2theta)

=1/(2cos^2theta-1)

=1/cos(2theta)=sec2theta=LHS

PROVED