#=sintheta - costheta/sintheta + sin theta/costheta#
#=(sin theta xx sin theta xx costheta)/(sin theta xx costheta) + (costheta xx costheta)/(costhetasintheta) + (sintheta xx sin theta)/(costhetasintheta)#
#=(sin^2thetacostheta + cos^2theta + sin^2theta)/(sinthetacostheta)#
#=((1 - cos^2theta)(costheta))/(sinthetacostheta)#
#=(1 - cos^2theta)/sintheta#
#=sqrt(((1 - cos^2theta)/sintheta)^2)#
#=sqrt((1 - 2cos^2theta + cos^4theta)/(sin^2theta))#
#=sqrt((1 - 2cos^2theta + cos^4theta)/(1 - cos^2theta))#
#=sqrt((-(cos2theta) + cos^4theta)/(1 - cos^2theta)#
Certainly a long proof, but it works, thankfully!
Hopefully this helps, and have a great day!
