Question

The height of a tower is h and the angle of elevation of the top of the tower is α. On moving a distance h/2 towards the tower, the angle of elevation becomes β. What is the value of cot α – cot β.

(a) 1/2

(b) 2/3

(c) 1

(d) 2

Answer 1

Correct option is (a) 1/2

Let AO = h be the tower O being the foot of it.

Then ∠OCA = α & ∠OBA = β, AO = h,