Trigonometric Equations Question 176
Question: The angle of elevation of a stationary cloud from a point 2500 m above a lake is $ 15^{o} $ and the angle of depression of its reflection in the lake is $ 45^{o} $ . The height of cloud above the lake level is
[IIT 1976]
Options:
A) $ 2500,\sqrt{3},metres $
B) 2500 metres
C) $ 500,\sqrt{3},metres $
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
- $ (H-h)\cot 15^{o}=(H+h)\cot 45^{o} $ or $ H=\frac{h,(\cot 15^{o}+1)}{(\cot 15^{o}-1)} $ Since $ h=2500 $ and substitute $ \cot 15^{o}=2+\sqrt{3} $ ,we get, $ H=2500,\sqrt{3} $ .
BETA
