Question

If $x\in [-4,3]$, then $x^2$ lies in

• A. $[9,16]$
• B. $[0,9]$
• C. $[0,16]$
• D. $[-16,9]$

Answer 1

The correct option is C $[0,16]$

$x\in [-4,3]$
$\Rightarrow -4\le x\le 3$
$\text{I}$.
$-4\le x\le 0$
$\Rightarrow 0\le x^2\le 16$
$\text{II}$.
$0\le x\le 3$
$\Rightarrow 0\le x^2\le 9$
$\therefore 0\le x^2\le 16$