Question

Which of the following is not a real number?
(a)√-4
(b)√5\4
(c)√11
(d)2.4​

Answer 1

Answer:

√-4 is not a real number.

cz there is no such no. whose square gives a negative number. But , as it's made up of signs and numbers, for formality it's treated as an imaginary number.