MCQ
જો $\cos (2{\sin ^{ - 1}}x) = \frac{1}{9}$ તો $x = $
- Aમાત્ર $ \frac{2}{3}$
- Bમાત્ર $ \frac{-2}{3}$
- ✓$ \frac{2}{3}, \frac{-2}{3}$
- D$ \frac{2}{3}$ અથવા $ \frac{-2}{3} $ પૈકી એકપણ નહીં
$ \Rightarrow \cos ({\sin ^{ - 1}}2x\sqrt {1 - {x^2}} ) = \frac{1}{9}$
==>$\cos ({\cos ^{ - 1}}\sqrt {1 - 4{x^2} + 4{x^4}} ) = \frac{1}{9}$
==> $1 - 2{x^2} = \frac{1}{9} \Rightarrow 2{x^2} = 1 - \frac{1}{9} = \frac{8}{9}$
==> ${x^2} = \frac{4}{9} \Rightarrow x = \pm \frac{2}{3}$.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
$\left| {\begin{array}{*{20}{c}} {{{\log }_e}\,a_1^ra_2^k}&{{{\log }_e}\,a_2^ra_3^k}&{{{\log }_e}\,a_3^ra_4^k} \\ {{{\log }_e}\,a_4^ra_5^k}&{{{\log }_e}\,a_5^ra_6^k}&{{{\log }_e}\,a_6^ra_7^k} \\ {{{\log }_e}\,a_7^ra_8^k}&{{{\log }_e}\,a_8^ra_9^k}&{{{\log }_e}\,a_9^ra_{10}^k}\end{array}} \right| = 0 $
તો ગણ $S$ માં રહેલા ઘટકોની સંખ્યા મેળવો.