Which option explains the meaning of (-∞,3]?
Answer and explanation
Correct answer: All real numbers less than or equal to 3
The interval (-∞,3] contains every real number extending indefinitely to the left and ending at 3. The round bracket at infinity is required because infinity is not an actual number or endpoint, while the square bracket at 3 means that 3 is included. In inequality form, the interval is {x∈R:x≤3}, so it includes negative numbers, zero, and positive numbers up to and including 3.
Frequently asked questions
What is the correct answer to this question?
All real numbers less than or equal to 3
Why is this the correct answer?
The interval (-∞,3] contains every real number extending indefinitely to the left and ending at 3. The round bracket at infinity is required because infinity is not an actual number or endpoint, while the square bracket at 3 means that 3 is included. In inequality form, the interval is {x∈R:x≤3}, so it includes negative numbers, zero, and positive numbers up to and including 3.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Equal sets and Subsets.
