If A+B+C=pi, then cos ^(2) ""(A)/(2) + c...

If `A+B+C=pi,` then `cos ^(2) ""(A)/(2) + cos ^(2) ""(B)/(2) - cos ^(2) ""(C )/(2)`

A

`2cos(A/2)cos(B/2)sin(C/2)`

B

`4cos(A/2)cos(B/2)sin(C/2)`

C

`1-2cos(A/2)cos(B/2)sin(C/2)`

D

`1-4cos(A/2)cos(B/2)sin(C/2)`

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