Mathematics - Quadratic Equation Question with Solution | TestHub

Since both roots are real ${\left(m+1\right)}^2-4\left(m+4\right)\ge 0$

$\Rightarrow m^2-2m-15\ge 0\Rightarrow \left(m-5\right)\left(m+3\right)\ge 0$

$\Rightarrow m\in (-\infty ,-3]\cup [5,\infty )$

$\Rightarrow A=(-\infty ,-3]\cup [5,\infty )$

$A-B=\left(-\infty ,-3\right)\cup [5,\infty )$ 

$A\cap B=\left\{-3\right\}$

$B-A=\left(-3,5\right)$

$A\cup B=R$