Question

prove that acos²A/2 +bcos²B/2+ccos²C/2=s+∆/R​

Answer 1

Answer:

LHS =a(bcosC−ccosB)=abcosC−accosB

=ab⋅

2ab

a

2

+b

2

−c

2

−ac⋅

2ac

a

2

+c

2

−b

2

, ..... use cosine rule

=

2

1

(a

2

+b

2

−c

2

−a

2

−c

2

+b

2

)=b

2

−c

2

=R.H.S.

Hence proved.

#HAVE A NICE DAY

Answer 2

Answer:

Sister i am Ayush ya it was my gf who answered your question