[" 2) "a,(1i)," Proved "tr ab-vdots(1)/(2)cos t((5cos n+3)/(5+3cos alpha))],[,=tan^(-1)((1)/(2)tan y_(2))]

(1)/(2)cos^(-1)((5cos x+3)/(5+3cos x))=tan^(-1)((1)/(2)(tan x)/(2))

(1)/(2)cos ^(-1)""((5 cos x +3)/(5+3 cos x))= tan^(-1)""((1)/(2)tan ""(x)/(2))

Prove that ""(1)/(2)cos^(-1)""((5cos x+3)/(5+3 cos x))= tan^(-1)""((1)/(2)tan""(x)/(2))

Prove that : (1)/(2) cos^(-1) ((1+ 2 cos x)/( 2+cosx) ) = tan^(-1) ((1)/(sqrt(3)) "tan" (x)/(2))

cos ^(-1) ""((cos x + cos y)/(1+cos x cos y))= 2 tan ^(-1) (tan ""(x)/(2) tan ""(y)/(2))

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

Prove that, tan^(-1)((3 sin 2x)/(5+3 cos 2x))+tan^(-1)((1)/(4) tan x)=x .

Show that cos^(-1) ((cos alpha+cos beta)/(1+cosalpha cosbeta))=2 tan^(-1)(tan (alpha/2) tan (beta/2))

cos[2(tan^(-1)((1)/(5))+tan^(-1)5)] = ________.

Prove that cos^(-1)[(cos alpha +cos beta)/(1+cos alpha cos beta)]=2tan^(-1)("tan"(alpha)/(2)"tan"(beta)/(2))