[" ILLUSTRATION "3.86],[" If "A+B+C=pi" ,prove that "],[sin^(2)(A)/(2)+sin^(2)(B)/(2)-sin^(2)(C)/(2)=1-2cos(A)/(2)cos(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)

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))

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)

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

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