In `DeltaABC`, if `A+C=2B`, prove that `2 cos ((A-C)/2) = (a+c)/sqrt(a^2 -ac+c^2)`

In DeltaABC , if 2 cos ((A-C)/2) = (a+c)/sqrt(a^2 -ac+c^2) [Note: All symbols used have their usual meaning in triangle ABC]

In DeltaABC , if b+c=3a , then prove that: cotB/2.cotC/2=2

In DeltaABC , prove that: (b+c)cos(B+C)/(2)=acos(B-C)/(2)

In DeltaABC , prove that: b(cosA-cosC)=2(c-a)cos^(2)B/2

In DeltaABC , prove that: (bcos^(2)C)/2+(c cos^(2)B)/2=s

In DeltaABC , prove that: a(cosC-cosB)=2(b-c)cos^(2)A/2

In DeltaABC , prove that: sin(B-C)/(2)=(b-c)/(a).cosA/2

In DeltaABC , prove that: a(cosB+cosC)=2(b+c)sin^(2)A/2 .

In DeltaABC , prove that: c(acosB-b cosA)=a^(2)-b^(2)

In DeltaABC , prove that: (a-b)/c=(sin(A-B)/(2))/(cosC/2)