If `a=cos theta+i sin theta` and `b= cos phi + i sin phi` then prove that `a^3/b^3+b^3/a^3=2cos3(theta-phi)`

If a = cos theta + isin theta , b = cosphi + isinphi , c = cos psi + i sin psi and a/b+b/c+c/a=2 then sin(theta-phi)+sin(phi-psi)+sin(psi-theta) equals

If a = cos theta + isin theta , b = cosphi + isinphi , c = cos psi + i sin psi and a/b+b/c+c/a=2 then sin(theta-phi)+sin(phi-psi)+sin(psi-theta) equals

If a = cos theta + isin theta , b = cosphi + isinphi , c = cos psi + i sin psi and a/b+b/c+c/a=2 then sin(theta-phi)+sin(phi-psi)+sin(psi-theta) equals

If sin theta - sin phi = a and cos theta + cos phi = b then prove that cos(theta + phi) = (a^(2)+b^(2) -2)/2

If sin theta+ sin phi= a and cos theta+ cos phi= b , find : sin (theta+ phi) .

If cos theta+cos phi=a and sin theta - sin phi=b , then: 2cos(theta + phi) =

If a=cos theta+i sin theta,b=cos phi+i sin phic=cos psi+i sin psi and (a)/(b)+(b)/(c)+(c)/(a)=2 then sin(theta-phi)+sin(phi-psi)+sin(psi-theta) equals

If the line joining the points (a cos theta , b sin theta) and (a cos phi, b sin phi) .Prove that the equation of this lines is x/a "cos" (theta + phi)/2 + y/b"sin" (theta + phi)/2 = "cos" (theta -phi)/2