Question 174393
I'll use {{{PHI}}} because &#952 won't render in the formula generator.


{{{((1/sec(PHI)) + (sin^2(PHI)/cos(PHI)))cos(PHI)}}}


We know that {{{cos(alpha)=1/sec(alpha)}}} so:


{{{((cos(PHI)) + (sin^2(PHI)/cos(PHI)))cos(PHI)=cos^2(PHI)+sin^2(PHI)=1}}}