If $\alpha$ and $\beta$ are the roots of the equation
2x(2x + 1) = 1, then $\beta$ is equal to :
Solution
$\alpha$ and
$\beta$ are the roots of the equation
<br>4x<sup>2</sup> + 2x – 1 = 0.
<br><br>$\therefore$ $\alpha$ + $\beta$ = $- {1 \over 2}$
<br><br>$\Rightarrow$ -1 = 2$\alpha$ + 2$\beta$
<br><br>and 4$\alpha$<sup>2</sup> + 2$\alpha$ - 1 = 0
<br><br>$\Rightarrow$ 4$\alpha$<sup>2</sup> + 2$\alpha$ + 2$\alpha$ + 2$\beta$ = 0
<br><br>$\Rightarrow$ $\beta$ = $- 2\alpha \left( {\alpha + 1} \right)$
About this question
Subject: Mathematics · Chapter: Complex Numbers and Quadratic Equations · Topic: Complex Numbers and Argand Plane
This question is part of PrepWiser's free JEE Main question bank. 223 more solved questions on Complex Numbers and Quadratic Equations are available — start with the harder ones if your accuracy is >70%.