" (iii) "cos^(2)(A)/(2)+cos^(2)(B)/(2)+cos^(2)(C)/(2)=2{1+sin(A)/(2)sin(B)/(2)sin(C)/(2)}

If A+B+C=180^(@), then prove that cos^(2)(A)/(2)+cos^(2)(B)/(2)+cos^(2)(C)/(2)=2(1+sin(A)/(2)sin(B)/(2)sin(C)/(2))

If A+B+ C =pi , then prove that cos ^(2) (A/2)+ cos ^(2) (B/2) +cos ^(2) (C/2)=2(1+sin . (A)/(2) sin. (B)/(2) sin. (C)/(2))

If A+B+C=180^0 , prove that : cos^2( A/2) + cos^2( B/2) + cos^2(C/2) = 2+2 sin(A/2) sin( B/2) sin( C/2)

If A+B+C=180^0 , prove that : cos^2( A/2) + cos^2( B/2) + cos^2(C/2) = 2+2 sin(A/2) sin( B/2) sin( C/2)

If A, B , C are angles of a triangle, then P. T sin ^(2) . (A)/(2)+ sin^(2). (B)/(2) - sin ^(2). (C)/(2) =1-2 cos. (A)/(2) cos. (B)/(2) sin .(C)/(2)

If : A+B+C= pi "then" : 1 - sin^(2)""(A)/(2) - sin^(2)""(B)/(2)+ sin^(2)""(C)/(2)= A) 2cos""(A)/(2) * cos sin ^(2)""(B)/(2) + sin^(2)""(C)/(2) B) 2 cos ""(B)/(2)* cos ""(B)/(2) * sin""(C)/(2) C) 2 cos ""(C)/(2)* cos ""(A)/(2) * sin""(B)/(2) D) 2 cos ""(A)/(2)* cos ""(B)/(2) * sin""(C)/(2)

sin^2(A/2)+sin^2(B/2)-sin^2(C/2)=1-2cos(A/2)cos(B/2)sin(C/2)

cos A + cos B + cos C = 1 + 4sin ((A) / (2)) sin ((B) / (2)) sin ((C) / (2))

If A+B+C=pi , prove that : sin^2( A/2) + sin^2( B/2) -sin^2( C/2) =1-2 cos( A/2) cos(B/2) sin( C/2)

In triangleABC,A+B+C=pi ,show that sin^2( A/2)+sin^2 (B/2)-sin^2 (C/2)=1-2cos(A/2)cos(B/2)sin(C/2)