If A, B and C are interior angles of a triangle ABC, then show that `sin((B+C)/2)=cos(A/2)`

If A , B and C are interior angles of triangle ABC ,then show that sin ((B+C)/( 2) )=cos (A) /(2)

If A , B and C are interior angles of a triangle ABC, then show that tan ((A+B) /(2)) =cot (C/2)

For any triangle ABC, prove that : sin""(B-C)/(2)=(b-c)/(a)cos((A)/(2))

If A,B,C are the angles of a triangle then prove that cosA+cosB-cosC=-1+4cos(A/2)cos(B/2)sin(C/2)

For any triangle ABC, prove that : (b+c)cos((B+C)/(2))=acos((B-C)/(2))

If A, B and C are angles of a triangle such that angleA is obtuse, then show tan B tan C lt 1.

If A,B and C are the angle of a triangle show that (i) |{:(sin2A,sinC,sinB),(sinC,sin2B,sinA),(sinB,sinA,sin2C):}|=0. (ii) |{:(-1+CcosB,cosC+cosB,cosB),(cosC+cosA,-1+cosA,cosB),(-1+cosB,-1+cosA,-1):}|=0.

For any triangle ABC, prove that : (a-b)/(c )=(sin((A-B)/(2)))/(cos((C)/(2)))

In any triangle ABC, prove that asin(B-C)+bsin(C-A)+csin(A-B)=0 .

If A,B and C are the angle of a non-right angled Delta ABC the value of |{:(tanA,1,1),(1,tanB,1),(1,1,tanC):}| is