If V={x∈Z: x²≤9}, what is n(V)?
Answer and explanation
Correct answer: 7
The governing concept is the cardinality of a set defined by an inequality. Since x²≤9, we have |x|≤3, or -3≤x≤3. The integers in this interval are -3,-2,-1,0,1,2,3, giving seven members. Thus n(V)=7 and option C is correct. Counting only positive integers gives 3, and forgetting zero or the negative values leads to the other distractors.
Frequently asked questions
What is the correct answer to this question?
7
Why is this the correct answer?
The governing concept is the cardinality of a set defined by an inequality. Since x²≤9, we have |x|≤3, or -3≤x≤3. The integers in this interval are -3,-2,-1,0,1,2,3, giving seven members. Thus n(V)=7 and option C is correct. Counting only positive integers gives 3, and forgetting zero or the negative values leads to the other distractors.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Number Systems.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
