BITSAT2014MathematicsTrigonometric Ratios & IdentitiesActual
An arch of a bridge is semi-elliptical with major axis horizontal. If the length the base is 9 meter and the highest part of the bridge is 3 meter from the horizontal; the best approximation of the height of the arch. 2 meter from the centre of the base is
Options
- A11 / 4 ~m
- B8 / 3 ~m
- C7 / 2 ~m
- D2 ~m
Correct answer
B. 8 / 3 ~m
Step-by-step solution
The equation of the ellipse is x² ( 9 2 )² + y² 9 =1 Where centre is assumed as origin and base as x -axis. Put x=2, we get 16 81 + y ² 9 =1 y = 65 3 8 3 ~m (approximately)