MCQ
Consider the equation ${x^2} + \alpha x + \beta  = 0$ having roots $\alpha ,\beta $ such that $\alpha  \ne \beta $ .Also consider the inequality $\left| {\left| {y - \beta } \right| - \alpha } \right| < \alpha $ ,then
  • inequality is satisfied by exactly two integral values of $y$
  • B
    inequality is satisfied by all values of $y \in  (-4, 2)$
  • C
    Roots of the equation are of same sign
  • D
    ${x^2} + \alpha x + \beta  > 0\,\forall \,x \in \,\left[ { - 1,0} \right]$

Answer

Correct option: A.
inequality is satisfied by exactly two integral values of $y$
a
$\alpha, \beta$ are roots of $\mathrm{x}^{2}+\alpha \mathrm{x}+\beta=0$ is

$\alpha+\beta=-\alpha$         .......$(1)$

and $\alpha \beta=\beta$           .......$(2)$

from $(1) $ and $(2) \alpha=1, \beta=-2$

Now $\| y+2|-1|<1$

$\Rightarrow-1<|\mathrm{y}+2|-1<1 \Rightarrow 0<|\mathrm{y}+2|<2$

$\Rightarrow-2<\mathrm{y}+2<2$ and $\mathrm{X} \neq-2$

$\Rightarrow \mathrm{y} \in(-4,0)-\{-2\}$

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