In any `DeltaABC`, prove that : `(b^2 - c^2) cos 2A + (c^2 - a^2) cos 2B + (a^2 - b^2) cos 2C =0`

Prove that a(b^(2) + c^(2)) cos A + b(c^(2) + a^(2)) cos B + c(a^(2) + b^(2)) cos C = 3abc

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

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

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

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

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

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 DeltaABC , prove that: (bcos^(2)C)/2+(c cos^(2)B)/2=s

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