In a `triangleABC`, (i) `a/cosA=b/cosB` (ii) `2 sin A cos B = sin C`

In triangleABC, a cosB-b cosA=

In a triangleABC, prove that a cos A+b cos B+c cos C=2a sin B sin C

In triangleABC, (b+c)cosA+(c+a)cosB+(a+b)cosC=

In triangleABC, (b+c)cosA+(c+a)cosB+(a+b)cosC=

IN triangleABC, (cosC+cosA)/(c+a)+(cosB)/(b)=

IN triangleABC, (cosC+cosA)/(c+a)+(cosB)/(b)=

If A,B,C are interior angles of a triangle ABC such that (cosA+cosB+cosC)^2+(sin A+sin B+sin C)^2=9 then the number of possible triangle is

In triangle ABC prove that (i) sinA=sin(B+C)" "(ii) sin2A=-sin(2B+2C) (iii) cosA=-cos(A+B)" " (iv) tan((A+B)/2)=cot. C/2

In triangle ABC prove that (i) sinA=sin(B+C)" "(ii) sin2A=-sin(2B+2C) (iii) cosA=-cos(A+B)" " (iv) tan((A+B)/2)=cot. C/2