Question 859666
Prove:
use x for theta:
sin(90 degree-theta) /1+sin theta+cos theta/1-cos(90 degree-theta) =2sec theta
{{{cos(x)/(1+sin(x))+(cos(x)/(1-sin(x)))}}}
{{{(cos(x)-cos(x)sin(x)+cos(x)+cos(x)sin(x))/(1-sin^2(x))=2sec(x)}}}
{{{2cos(x)/cos^2(x)}}}
{{{2/cos(x)=2sec(x)}}}
verified: left side=right side