Trigonometric Equations Question 74
Question: If $ \cos \theta =-\frac{1}{\sqrt{2}} $ and $ \tan \theta =1 $ , then the general value of $ \theta $ is
Options:
A) $ 2n\pi +\frac{\pi }{4} $
B) $ (2n+1),\pi +\frac{\pi }{4} $
C) $ n\pi +\frac{\pi }{4} $
D) $ n\pi \pm \frac{\pi }{4} $
Show Answer
Answer:
Correct Answer: B
Solution:
- $ \cos \theta =-\frac{1}{\sqrt{2}}\Rightarrow \theta =\frac{3\pi }{4},,\frac{5\pi }{4} $ ; $ \tan \theta =1\Rightarrow \theta =\frac{\pi }{4},,\frac{5\pi }{4} $
$ \therefore $ The general value is $ 2n\pi +\frac{5\pi }{4} $ or $ (2n+1)\pi +\frac{\pi }{4} $ .
BETA
