- The angle of elevation of the top of a tower, vertically erected in the middle of a paddy field, from two points on a horizontal line through the foot of the tower are given to be α and β (α>β). The height of the tower is h unit. A possible distance (in the same unit) between the points is

A

$$ \frac {h(cot\beta-cot\alpha)}{cos(\alpha+\beta)}$$

B

$${h(cot\alpha-cot\beta)}$$

C

$$ \frac {h(tan\beta-tan\alpha)}{tan\alpha tan\beta}$$

D

$${h(cot\alpha+cot\beta)}$$