Trigonometric Equations Question 64

Question: If $ \sin \theta =\sqrt{3}\cos \theta ,-\pi <\theta <0 $ , then $ \theta = $

[MP PET 1992]

Options:

A) $ -\frac{5\pi }{6} $

B) $ -\frac{4\pi }{6} $ $ $

C) $ \frac{4\pi }{6} $

D) $ \frac{5\pi }{6} $

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Answer:

Correct Answer: B

Solution:

  • $ \tan \theta =\sqrt{3}=\tan \frac{\pi }{3}\Rightarrow \theta =n\pi +\frac{\pi }{3} $ For $ -\pi <\theta <0 $ $ Putn=-1 $ , we get $ \theta =-\pi +\frac{\pi }{3}=\frac{-2\pi }{3}\text{or }\frac{-4\pi }{6} $ .