" (iii) "a^(2)-b^(2)-c^(2)-2bc

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 a /_\ABC if a^(2)-b^(2)-c^(2)+(x-2)bc=0 then x be equal to

In a /_\ABC if a^(2)-b^(2)-c^(2)+(x-2)bc=0 then x be equal to

Factorise : 3a^(2)-b^(2)-c^(2)+2ab-2bc+2ca

Prove in any triangle ABC that (i) a^(2)+b^(2)+c^(2)=2(bc cos A +ca cos B+ ab cos C) (ii) (b+c) cos A+(c+a)cos B+(a+b) cos C = a+b+c .

Factorise : a^(2)-b^(2)-c^(2)+2bc

Factorise : a^(2) - b^(2) - c^(2) +2bc

In a triangle ABC , if a^(2)-b^(2)-c^(2)=bc(lambda^(2)-2lambda-1) , then

If a+b+c=0 then prove the following. a^(2)+b^(2)+c^(2) = -2(bc+ca+ab)