Mathematics - 3D-Coordinate Geometry Question with Solution | TestHub

$f\left(x\right)$has three real roots if$a>4$

$f\left(x\right)$has only one real roots if$a>4$

$f\left(x\right)$has three real roots if$a< -4$

$f\left(x\right)$has three real roots if$-4<a<4$