IF `A+B+C =pi` , then P.T `cos^2""A/2+cos^2""B/2+cos^2""C/2=2(1+sin""A/2sin""B/2sin""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 =pi/2 , prove that : cos^2 A +cos^2 B+cos^2 C= 2+2 sin A sin B sin C .

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

If A + B + C = pi then prove that cos A + cos B + cos C = 1 + 4 sin(A/2) .sin(B/2).sin(C/2)

If A + B + C = pi , prove that cos A + cos B + cos C= 1 + 4 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^(@), 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)/(2) , then prove that cos 2A + cos 2B + cos 2C=1+4 sin A sin B sin C .

If A + B + C =pi , prove that : cos 2A + cos 2B -cos 2C= 1-4sin A sin B cos C .