Question

The roster form of the set $\{x:x$ is a real number and $x^3=3x^2-2x\}$

• A. $\{1,2\}$
• B. $\{0,1,2\}$
• C. $\{1,2,\varphi \}$
• D. $\{0,\varphi ,1,2,3\}$

Answer 1

The correct option is B $\{0,1,2\}$

$x^3=3x^2-2x$
$\Rightarrow x^3-3x^2+2x=0$
$\Rightarrow x(x-1)(x-2)=0\Rightarrow x=\{0,1,2\}$

$\therefore$ Roster form $=\{0,1,2\}$