Theorem 3 :If `A+B+C=pi` 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=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

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

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

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

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