a^(2)=(b-c)^(2)cos^(2)((A)/(2))+(b+c)^(2)sin^(2)((A)/(2))

In Delta ABC , prove that (b - c)^(2) cos^(2) ((A)/(2)) + (b + c)^(2) sin^(2) ((A)/(2)) = a^(2) .

In DeltaABC" prove that "(b-c)^(2)cos^(2).(A)/(2)+(b+c)^(2)sin^(2).(A)/(2)=a^(2)

In DeltaABC prove that (b-c)^(2)cos^(2).(A)/(2)+(b+c)^(2)sin^(2).(A)/(2)=a^(2)

In DeltaABC , prove that: (b-c)^(2)cos^(2)A/2+(b+c)^(2)sin^(2)A/2=a^(2)

In DeltaABC , prove that: (b-c)^(2)cos^(2)A/2+(b+c)^(2)sin^(2)A/2=a^(2)

For DeltaABC prove that, (a-b)^(2)cos^(2)""(C)/(2)+(a+b)^(2)sin^(2)""(C)/(2)=c^(2)

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

(cos ^(2) ((B-C)/( 2)) )/( (b+c)^(2))+( sin ^(2)((B-C)/( 2)) )/( (b-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))