Easy math question? 10 pts?

Question

what does this mean

(-infinity, 5]

(-infinity, infinity)

Answer 1

This is probably notation to describe intervals.  The [ and ] bracket means that the interval includes the left or right values, and the ( and ) brackets mean that the interval includes every number greater than or less than the value.  So:

(a, b] would be an interval containing all values greater than a and less than or equal to b.

[a, b] would indicate an interval containing all values greater than or equal to a and less than or equal to b.

(a, b) would indicate an interval containing all values between a and b, not including a or b.

When we put infinity or -infinity in the brackets, we mean that the interval extends to all positive or negative values.  So:

(-infinity, 5] includes all numbers less than or equal to 5.

(-infinity, infinity) should include every single number.

Hope this helps.

Answer 2

(-infinity, 5] means the domain of all numbers between negative infinity and 5, including 5.

(-infinity, infinity) means the domain of all numbers.

Answer 3

infinity is drawn like an 8 laying on its side.

It means that the answer does not stop on the graph at a certain number.  It just goes on and on into infinity.

If it's -infinity then the arrow on the graph is going in the negative direction



If it's positive infinity then it's going in the positive direction on the graph.

Answer 4

(-infinity, 5] means the interval from - infinity to 5, including 5 because of the bracket, but not including - infinity because of the parenthesis.

It's like writing   -infinity < x <= 5

(-infinity, infinity) means the interval from -infinity to infinity, not including those as endpoints.

Hope this helps !

Brackets mean to include

Parenthesis mean NOT to include.

Answer 5

I can only guess that the answer is 0.

Answer 6

first one means the set of numbers from negative infinity to 5, but not including  5.

the second one means the set of numbers from negative infinity to infinity, or all real numbers.

make it a good day

Answer 7

(-infinity, 5] means the set of all numbers between negative infinity and 5, including 5.

(-infinity, infinity) means the set of all numbers.