Choose the correct answer in If a,b,c are in A.P., then the determinant (fig 1) is:

fig 1:

(A) 0  

(B) 1  

(C)     

(D)  

solution:

According to question,  ……….(i)

Let 

=  

= 

[From eq. (i)] = 0 [ R₂ and R₃ have become identical]

Therefore, option (A) is correct.