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

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

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

In any DeltaABC , prove that : (b^2 - c^2)/a^2 = (sin (B-C))/(sin(B+C))

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

In any DeltaABC , prove that : tan (A/2 + B) = (c+b)/(c-b) tan (A/2)

In DeltaABC , prove that: (b^(2)-c^(2)+a^(2))tanC=(b^(2)+c^(2)-a^(2))tanA

In DeltaABC, prove that cosA=(b^2+c^2-a^2)/(2b c) by vector method.

In any DeltaABC , 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

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

In any DeltaABC , prove that: (a+b-c)/(a+b+c) = tan (A/2) tan (B/2)