From a point on the ground the angle of elevation of top of a tower is is x. On moving 'a' meters towards the tower, the elevation changes to y. Find the height of the tower?
Answer & explanation
Correct answer: option 1
tan x = \(\frac{PQ}{SQ}\) tan y = \(\frac{PQ}{RQ}\)
SR = SQ - RQ
⇒ a = \(\frac{PQ}{tan x}\) - \(\frac{PQ}{tan y}\)
⇒ PQ (\(\frac{1}{tanx}\) - \(\frac{1}{tany}\)) = a
⇒ PQ = \(\frac{a tanx.tany}{tany - tanx}\)