Q85 / 150 · MHT CET 2019 (02 May Shift 1) · Mathematics

If $A = \{x \in R : x^{2} - 5 |x| + 6 = 0\},$ then $n (A) =$ ________

A
$2$
B
$0$
C
$1$
Correct answer
D
$4$

Solution

Given:

A = \{x \in R : x^{2} - 5 |x| + 6 = 0\}

x^{2} - 5 |x| + 6 = 0 \Rightarrow {|x|}^{2} - 5 |x| + 6 = 0

|x| = 2, 3 \Rightarrow x = \pm 2, \pm 3

Hence,

n (A) = 4

Hence, the correct answer is option: 'D'.

Relevant Questions

Let be a non-empty subset of . Consider the following statement: p : There is a rational number such that . Which of the following statement16 May, 2024 (M)Questions on number of relations and sets
If . Then the number of subsets of the set each having at least 3 elements are15 May, 2024 (M)Questions on number of relations and sets
Let . Relation are as follows:20 Sep, 2021 (E)Questions on number of relations and sets
If , then the total number of relations from set to set are16 Oct, 2020 (M)Questions on number of relations and sets
Given If is a relation from to such that with , then range of is14 Oct, 2020 (E)Questions on number of relations and sets
If is a prime number, , then the number of elements of power set of is13 Oct, 2020 (E)Questions on number of relations and sets