Trigonometric Identities Question 261
Question: For what values of x is the equation $ 2,sin,\theta =x+\frac{1}{x} $ valid?
Options:
A) $ x=\pm 1 $
B) All real numbers x
C) $ -1<x<1 $
D) $ x>1 $ and $ x<-1 $
Show Answer
Answer:
Correct Answer: A
Solution:
Given: $ 2\sin \theta =x+\frac{1}{x} $ We know that $ -1\le \sin \theta <1, $ $ -2\le 2\sin \theta <2 $ So, $ -2\le x+\frac{1}{x}<2 $ Thus, the given equation is valid only if $ x=1 $ or $ x=-1 $
BETA
