Functions Question 643
Question: The range of $ f(x)=\cos x-\sin x $ is
[MP PET 1995; Pb. CET 2001]
Options:
A) $ (-1,\ 1) $
B) $ [-1,,\ 1) $
C) $ [ -\frac{\pi }{2},\ \frac{\pi }{2} ] $
D) $ [-\sqrt{2},\ \sqrt{2}] $
Show Answer
Answer:
Correct Answer: D
Solution:
Since maximum and minimum values of $ \cos x-\sin x $ are $ \sqrt{2} $ and $ -\sqrt{2} $ respectively, therefore range of $ f(x) $ is $ [-\sqrt{2},\sqrt{2}]. $
BETA
