IF A,B,C are angles in the triangle, then prove that
`cosA+cosB-cosC=-1+4cos""A/2.cos""B/2.sin""C/2`

If A,B,C are the angles of a triangle then prove that cosA+cosB-cosC=-1+4cos(A/2)cos(B/2)sin(C/2)

If A,B,C are the angles of a triangle then prove that cosA+cosB-cosC=-1+4cos(A/2)cos(B/2)sin(C/2)

If A,B,C are the angles of a triangle then prove that cos A+cos B-cos C=-1+4cos((A)/(2))cos((B)/(2))sin((C)/(2))

If A,B,C are angles in a triangle , then prove that cosA+cosB+cosC=1+4sin. (A)/(2)sin. (B)/(2) sin. (C)/(2)

If A+B+C= pi ,prove that :cosA+cosB-cosC=-1+4cosA/2cosB/2sinC/2.

If A, B, C are angles of a triangle , prove that cos 2A - cos 2B + cos 2C =1 -4 sin A cos B sin C

If A+B+C=pi , prove that : cosA + cosB-cosC=4cos(A/2) cos(B/2) sin(C/2) -1

If A+B+C=pi , prove that : cosA + cosB-cosC=4cos(A/2) cos(B/2) sin(C/2) -1

In triangleABC,A+B+C=pi ,show that cosA+cosB-cosC=4cos(A/2)cos(B/2)sin(C/2)-1

If A+B+C=0 then show that 1+cosA+cosB+cosC=4"cos"A/2"cos"B/2"cos"C/2