Class 10

Math

All topics

Some Applications of Trigonometry

The angle of elevation of an object from a point $P$ on the level ground is $α$. Moving $d$ meters on the ground towards the object, the angle of elevation is found to be $β$, then the height (in meters) of the object is

- $dtanα$
- $dcotβ$
- $cotα+cotβd $
- $cotα−cotβd $

$tanβ=ah $

$⇒tanα=d+tanβh h $

$⇒dtanα=h−htanβtanα $

$⇒dtanα=tanβh(tanβ−tanα) $

$⇒h=(tanβ−tanα)dtanα tanβ $

$⇒h=(cotα−cotβ)d $