[" In any triangle "ABC" ,then by vectors,prove that "(6-8):],[" 6."(i)a^(2)=b^(2)+c^(2)-2bc cos A]

In any triangle ABC, then by vectors, prove that : c^2=a^2+b^2-2ab cos C .

With usual notations, in any triangle ABC, prove the following by vector method . (i) a^(2)=b^(2)+c^(2)-2bc cos A (ii) b^(2)=c^(2)+a^(2)-2bc cosB (iii) c^(2)=a^(2)+b^(2)-2bc cosC

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

Using vector method prove that in any triangle ABC a^2=b^2+c^2-2bc cos A .

Using vector method prove that in any triangle ABC a^2=b^2+c^2-2bc cos A .

For any triangle ABC, prove that (cos A)/(a)+(cos B)/(b)+(cos C)/(c)=(a^(2)+b^(2)+c^(2))/(2abc)

In any triangle ABC, prove that : a (cos C - cos B) = 2 (b-c) cos^2 frac (A)(2) .

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

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

Prove by vector method that in a Delta ABC, c^(2) = a^(2) + b^(2) - 2ab cos C .