A tower of height subtends an angle at a point on the level of the foot of the tower…

MATHEMATICS · Single correct · A Level · Mathematics · Trigonometry · Trigonometry

Problem

A tower of height

b

subtends an angle at a point

O

on the level of the foot of the tower and at a distance

a

from the foot of the tower. If a pole mounted on the tower also subtends an equal angle at

O

, the height of the pole is (1)

b \left( \frac{a^2 - b^2}{a^2 + b^2} \right)

(2)

b \left( \frac{a^2 + b^2}{a^2 - b^2} \right)

(3)

a \left( \frac{a^2 - b^2}{a^2 + b^2} \right)

(4)

a \left( \frac{a^2 + b^2}{a^2 - b^2} \right)