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4-1.Complex numbers
hard
यदि $\sqrt 3 + i = (a + ib)(c + id)$, तब ${\tan ^{ - 1}}\left( {\frac{b}{a}} \right) + $${\tan ^{ - 1}}\left( {\frac{d}{c}} \right)$ का मान है
A
$\frac{\pi }{3} + 2n\pi ,n \in I$
B
$n\pi + \frac{\pi }{6},n \in I$
C
$n\pi - \frac{\pi }{3},n \in I$
D
$2n\pi - \frac{\pi }{3},n \in I$
Solution
(b) $\sqrt 3 + i = (a + ib)(c + id)$
$\therefore ac – bd = \sqrt 3 $एवं $ad + bc = 1$
अब $tan^{-1}$ $\left( {\frac{b}{a}} \right) + {\tan ^{ – 1}}\left( {\frac{d}{c}} \right)$ $\begin{array}{l} = {\tan ^{ – 1}}\left( {\frac{{\frac{b}{a} + \frac{d}{c}}}{{1 – \frac{b}{a}.\frac{d}{c}}}} \right) = {\tan ^{ – 1}}\left( {\frac{{bc + ad}}{{ac – bd}}} \right) = {\tan ^{ – 1}}\left( {\frac{1}{{\sqrt 3 }}} \right)\\\end{array}$
$ = n\pi + \frac{\pi }{6},n \in I$
Standard 11
Mathematics