Question

(1-cosA)/(1+cosA)=tan^2(A/2)

Answer 1

Answer:

How do I prove that tan(A/2) = (sinA)/(1+cosA)? ... If cosA/cosB=n and sinA/sinB=m, can one prove that (m^2-n^2) (sinB) ^2=1-n^2? ... SinA / (1 + CosA)=sinA/2 / CosA/2 =Tan A/2