If sinα+sinβ=a and cosα−cosβ=b, then tanα−β2=
If sinα+sinβ=α and cosα−cosβ=b, then tanα−β2=
If sin α+sin β=a and cos α+cos β=b, prove that
(i) sin(α+β)=2aba2+b2
(ii) cos(α−β)=a2+b2−22