Question

Plzz answer this question,.., Only best answer will be marked as BRAINLIST,,​

Answer 1

Question :

In triangle ABC prove that

if cosA + cosC = 2(1- cosB), then a,b,c are in AP

Formulas Used :

1) cos A + cos B =2cos(A+B)/2 cos (A-B)/2

2) if a,b,c are in AP

then , 2b = a+c

Solution :

Refer to the attachment !