In triangle ABC, prove that `cos(A/2)+cos(B/2)+cos(C/2)=4cos(pi-A)/4cos(pi-B)/4cos(pi-C)/4`

In triangle ABC,prove that cos((A)/(2))+cos((B)/(2))+cos((C)/(2))=4(cos(pi-A))/(4)(cos(pi-B))/(4)(cos(pi-C))/(4)

In triangle ABC, prove that cos .(A)/(2)+cos.(B)/(2)+cos. (C)/(2) =4 cos .(pi-A)/(4)cos. (pi-B)/(4) cos.(pi-C)/(4)

If A +B+C = 180^circ , prove that cos A/2+ cos B/2 +cos C/2 = 4cos (pi-A)/4 * cos(pi-B)/4 cos(pi-C)/4

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

In Delta ABC , prove that cos. (A)/(2)+cos. (B)/(2) - cos .(C)/(2)=4cos .(pi+A)/(4) cos. (pi+B)/(4) cos. (pi-C)/(4)

If A+B+C=180^(@) then prove the following: "cos"A/2+"cos"B/2+"cos"C/2 =4cos((pi-A)/4)cos((pi-B)/4)cos((pi-C)/4)

In triangle ABC , prove that sin .(A)/(2)+ sin. (B)/(2) -sin. (C)/(2)=-1+4 cos.(pi-A)/(4)cos. (pi-B)/(4)sin. (pi-C)/(4)

If A+B+C=pi prove that cos^(2) A+cos^(2) B+cos^(2) C=1 - 2cos A cos B cos C .

Prove that 4cos((2pi)/7).cos(pi/7)-1=2cos((2pi)/7) .