- Home
- Standard 11
- Mathematics
Trigonometrical Equations
easy
यदि ${\sin ^2}\theta + \sin \theta = 2$, तो $\theta $ का व्यापक मान होगा
A
$n\pi + {( - 1)^n}\frac{\pi }{6}$
B
$2n\pi + \frac{\pi }{4}$
C
$n\pi + {( - 1)^n}\frac{\pi }{2}$
D
$n\pi + {( - 1)^n}\frac{\pi }{3}$
Solution
(c) ${\sin ^2}\theta + \sin \theta – 2 = 0$
$\Rightarrow (\sin \theta – 1)\,(\sin \theta + 2) = 0$
$ \Rightarrow $ $\sin \theta \ne – 2$ ,
$\therefore \,\,\sin \theta = 1 = \sin \pi /2$
$ \Rightarrow $ $\theta = n\pi + {( – 1)^n}\frac{\pi }{2}$.
Standard 11
Mathematics