Which of the following is not a real number?

Answer:
D
Step-by-step explanation:
by definition, the square root of an negative number is known as an imaginary number. i.e Not a real number
[tex]\sqrt{-2}[/tex] = [tex]\sqrt{2}[/tex][tex]\sqrt{-1}[/tex] = [tex]\sqrt{2}[/tex]i (imaginary number)
The [tex]\sqrt{-2}[/tex] is not a real number.
The following information should be considered with respect to the real number:
Therefore, the first three options are considered to be the real number.
Thus we can conclude that the [tex]\sqrt{-2}[/tex] is not a real number.
Learn more: brainly.com/question/17429689