If `(sin^(4)phi)/(a)+(cos^(4)phi)/(b)=(1)/(a+b)` then prove that `(sin^(8)phi)/(a^(3))+(cos^(8)phi)/(b^(3))=((1)/(a+b))^(3)`

sin^(4)phi=(3)/(8)+(1)/(8)cos4 phi-(1)/(2)cos2 phi

sin(theta+phi)/cos(theta-phi)=(1-x)/(1+x) then prove that tan(pi/4-theta)tan(pi/4+phi)=x

If sin theta+sin phi=(1)/(4) and cos theta+cos phi=(1)/(5) then value of sin(theta+phi) is

If tan(theta)/(2)=sqrt((a-b)/(a+b))tan(phi)/(2), prove that cos theta=(a cos phi+b)/(a+b cos phi)

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

Prove that: tan^(-1)[(3 sin 2 phi)/(5+3cos 2phi)]+tan^(-1)[(1)/(4) tan phi]=phi

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 sin2 theta+sin2 phi=(1)/(2) and cos2 theta+cos2 phi=(3)/(2), then cos^(2)(theta-phi)=(A)(3)/(8)(B)(5)/(8)(C)(3)/(4)(D)(5)/(4)

If sin theta+sin phi=sqrt(3)(cos phi-cos theta), prove that sin3 theta+sin3 phi=0

If sin theta+sin phi=sqrt(3)(cos phi-cos theta)), prove that sin3 theta+sin3 phi=0