किसी `triangleABC` में सिद्ध करे कि
`b cos^(2)""(C)/(2) + c cos^(2)""(B)/(2) = c cos^(2)""(A)/(2) + a cos^(2)""(C)/(2) = a cos^(2)""(B)/(2) + b cos^(2)""(A)/(2) = ( a + b +c )/(2)`

a cos ^(2) "" ( A) /(2) + b cos ^(2) "" ( B)/(2) = c cos ^(2) "" ( C) /(2) =

If : A+B+C= pi "then" : 1 - sin^(2)""(A)/(2) - sin^(2)""(B)/(2)+ sin^(2)""(C)/(2)= A) 2cos""(A)/(2) * cos sin ^(2)""(B)/(2) + sin^(2)""(C)/(2) B) 2 cos ""(B)/(2)* cos ""(B)/(2) * sin""(C)/(2) C) 2 cos ""(C)/(2)* cos ""(A)/(2) * sin""(B)/(2) D) 2 cos ""(A)/(2)* cos ""(B)/(2) * sin""(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))

In Delta ABC prove that 2(b cos^(2)((C)/(2))-c cos^(2)((B)/(2)))=a+b+c

(iv) a^(2)(cos^(2) B - cos^(2)C) + b^(2) (cos^(2) C- cos^(2)A) + c^(2) (cos^(2)A- cos^(2)B)=0

(bc) / (a) cos ^ (2) ((A) / (2)) + (ca) / (b) cos ^ (2) ((B) / (2)) + (ab) / (c ) cos ^ (2) ((C) / (2)) =

(bc) / (a) cos ^ (2) ((A) / (2)) + (ca) / (b) cos ^ (2) ((B) / (2)) + (ab) / (c ) cos ^ (2) ((C) / (2)) =

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

a^(2)(cos^(2)B-cos^(2)C)+b^(2)(cos^(2)C-cos^(2)A)+c^(2)(cos^(2)A-cos^(2)B)=0