COMEDK2023Evening ShiftMathematicsSets and RelationsActual
Which of the following is a singleton set?
Options
- Ax:|x|<4, x N
- Bx: x^2=4, x N
- Cx:|x|<-4, x N
- Dx: x^2=4, x R
Correct answer
B. x: x^2=4, x N
Step-by-step solution
For option (1), the set is x : |x| For option (2), the set is x : x^2 = 4, x N . Solving x^2 = 4 gives x = 2 or x = -2 . Since x must be a natural number, x = 2 . Thus, the set is 2 , which is a singleton set. For option (3), the set is x : |x| For option (4), the set is x : x^2 = 4, x R . Solving x^2 = 4 gives x = 2 or x = -2 . Thus, the set is -2, 2 , which is not a singleton set. Answer: x: x^2=4, x N