Trigonometric Identities Question 370
Question: $ \frac{1}{\sin 10{}^\circ }-\frac{\sqrt{3}}{\cos 10{}^\circ } $ =
[IIT 1974]
Options:
A) 0
B) 1
C) 2
D) 4
Show Answer
Answer:
Correct Answer: D
Solution:
$ \frac{1}{\sin 10{}^\circ }-\frac{\sqrt{3}}{\cos 10{}^\circ } $ $ =\frac{2,( \frac{1}{2}\cos 10^{o}-\frac{\sqrt{3}}{2}\sin 10^{o} )}{\frac{2}{2},( =\frac{\cos 10^{o}-\sqrt{3}\sin 10^{o}}{\sin 10^{o}\cos 10^{o}}\sin 10^{o}\cos 10^{o} )} $ $ =\frac{4,\sin ,(30^{o}-10^{o})}{\sin ,20^{o}}=\frac{4,\sin ,20^{o}}{\sin ,20^{o}}=4 $ .
BETA
