In any `DeltaABC`, prove that : `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`

In any Delta ABC, prove that :a(b cos C-c cos B)=b^(2)-c^(2)

In any DelataABC prove that "a(cos C - cos B)=2(b-c)cos"^(2)A/2

In any Delta ABC, prove that :a cos A+b cos B+c cos C=2a sin B sin C

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

In any triangle ABC, prove that following: (cos^(2)B-cos^(2)C)/(b+c)+(cos^(2)C-cos^(2)A)/(c+a)+(cos^(2)A-cos^(2)B)/(a+b)=0

In any Delta ABC, prove that :a^(2)+b^(2)+c^(2)=2(bc cos A+ca cos B+ab cos C)

If A+B+C=180^0 , prove that : cos^2 A + cos^2 B + cos^2 C + 2cosA cosB cosC=1 .

In any DeltaABC , prove that (cos2A)/a^(2)-(cos2B)/b^(2)=(1/a^(2)-1/b^(2))

In any ABC, prove that: 2(bosA+ca cos B+ab cos C)=a^(2)+b^(2)+c^(2)