Using vectors , prove that in a triangle ABC
` a/(sin A) = b/(sin B) = c/(sin C) `
where a,b,c are lengths of the ideas opposite to the angles A,B,C of triangle ABC respectively .

Using vectors , prove that in a triangle ABC a^(2)= b^(2) + c^(2) - 2bc cos A where a,b,c are lengths of the ideas opposite to the angles A,B,C of triangle ABC respectively .

Using vectors , prove that in a triangle ABC a = b cos C + c cos B where a,b,c are lengths of the ideas opposite to the angles A,B,C of triangle ABC respectively .

If in a triangle ABC, sin A, sin B, sin C are in A.P, then

In triangle ABC, (i) asin(A/2 + B) = (b+c) sin A/2

If in a triangle ABC, b sin B = c sin C, then the triangle is-

ABC is a triangle. sin((B+C)/(2))=

In any triangle ABC, show that (a sin C)/(b - a cosC)= tanA .

If angle C of triangle ABC is 90^0, then prove that tanA+tanB=(c^2)/(a b) (where, a , b , c , are sides opposite to angles A , B , C , respectively).

In a triangle ABC,sin A-cos B=cosC,then angle B is

Let PQR be a triangle of area Delta with a=2,b=7/2 and c=5/2 , where a,b and c are the lengths of the sides of the triangle opposite to the angles at P,Q and R respectively. Then ((2sinP-sin2P)/ (2sinP+sin2P)) equals