Which of the following is an empty set? | Mathematics | SolveeIt

Which of the following is an empty set?

$\\{ x | x$ is a real number and $x^2 - 1 = 0\\}$

$\\{ x | x$ is a real number and $x^2 + 3 = 0\\}$

$\\{ x | x$ is a real number and $x^2 - 9 = 0\\}$

$\\{ x | x$ is a real number and $x^2= x +2\\}$

Answer

$\\{ x | x$ is a real number and $x^2 + 3 = 0\\}$

Explanation

$x^2 + 3 = 0$
$\Rightarrow \, x = \sqrt{-3} \in C$
$\Rightarrow \, x$ is not a real number
$\therefore$ It is an empty set.

Mathematics Question on Sets