A + B + C = π

(cotA+cotB+cotC)÷(cotA×cotB×cotC) =

(a) 1

(b) cotAcotBcotC

(c) -1

(d) 0

My attempt at solution:

Let A = B = C = π÷3

Then,

cot(A) + cot(B) + cot(C) = 3 × cot(π÷6) = 3 × (1÷√3) = √3

And,

cotA × cotB × cotC = (1÷√3)^(3) =1÷(3√3)

Therefore, answer should be 9.

What am I doing wrong?

Source: BITSAT Paper 2012.

Dhruvit Raithatha

9 Years agoGrade 12th pass