- Home
- Standard 11
- Mathematics
1.Set Theory
easy
Which of the following is the empty set
A
$\{ x:x$ is a real number and ${x^2} - 1 = 0\} $
B
$\{ x:x$ is a real number and ${x^2} + 1 = 0\} $
C
$\{ x:x$ is a real number and ${x^2} - 9 = 0\} $
D
$\{ x:x$ is a real number and ${x^2} = x + 2\} $
Solution
(b) Since ${x^2} + 1 = 0,$ gives ${x^2} = – 1$
$ \Rightarrow $ $x = \pm$ $ i x$ is not real but $x$ is real (given) No value of $x$ is possible.
Standard 11
Mathematics
