If A = {x : x ∈ ℝ and −4 < x ≤ 1}, which is the interval form of A?
Answer and explanation
Correct answer: (−4, 1], open at −4 and closed at 1
The inequality −4 < x means that x is greater than −4, but x cannot equal −4; therefore, −4 is excluded and receives a round bracket. The inequality x ≤ 1 means that x may equal 1; therefore, 1 is included and receives a square bracket. Hence A is written in interval notation as (−4, 1].
Frequently asked questions
What is the correct answer to this question?
(−4, 1], open at −4 and closed at 1
Why is this the correct answer?
The inequality −4 < x means that x is greater than −4, but x cannot equal −4; therefore, −4 is excluded and receives a round bracket. The inequality x ≤ 1 means that x may equal 1; therefore, 1 is included and receives a square bracket. Hence A is written in interval notation as (−4, 1].
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
