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Trigonometrical Equations
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यदि $\tan \theta + \tan 2\theta + \sqrt 3 \tan \theta \tan 2\theta = \sqrt 3 ,$ तब
A
$\theta = (6n + 1)\pi /18,\,\forall n \in I$
B
$\theta = (6n + 1)\pi /9,\,\forall n \in I$
C
$\theta = (3n + 1)\pi /9,\,\forall n \in I$
D
इनमें से कोई नहीं
Solution
दिया गया सम्बन्ध है,
$\tan \theta + \tan 2\theta + \sqrt 3 \tan \theta \tan 2\theta = \sqrt 3 $
$\Rightarrow$ $\,\tan \theta + \tan 2\theta = \sqrt 3 (1 – \tan \theta \tan 2\theta )$
$\Rightarrow$ $\frac{{\tan \theta + \tan 2\theta }}{{1 – \tan \theta \tan 2\theta }} = \sqrt 3 $
$\Rightarrow$ $\tan 3\theta = \tan (\pi /3)$
$\Rightarrow$ $3\theta = n\pi + \frac{\pi }{3}$
$\Rightarrow$ $\theta = (3n + 1)\frac{\pi }{9}$.
Standard 11
Mathematics