NDA2019MathematicsHeights and DistancesActual
The angle of elevation of a tower of height h from a point A due South of it is x and from a point B due East of A is y . If AB = z , then which one of the following is correct ?
Options
- Ah ^2 ( ^2 y- ^2 x )=z^2
- Bz^2 ( ^2 y- ^2 x )=h^2
- Ch ^2 ( ^2 y - ^2 x )= z ^2
- Dz^2 ( ^2 y- ^2 x )=h^2
Correct answer
A. h ^2 ( ^2 y- ^2 x )=z^2
Step-by-step solution
from figure (iii), h ^2 ^2 y= z ^2+ h ^2 ^2 x z ^2= h ^2 ( ^2 y - ^2 x )