question_answer

The height of a tower is h m and the angle of elevation of the top of the tower is a. On moving a distance h/2 towards the tower, the angle of elevation becomes P. What is the value of\[\cot \alpha -\cot \beta \]?

A) \[\frac{1}{2}\]                   

B)        \[\frac{2}{3}\]

C) 1                             

D)        2