Write the interval notation corresponding to the set notation
{x | x < –7}.
Since
[-5,8) is the same as {x|-5=<x<8}
we have
{x|x<-7}
in interval notation
[-infinity, -7)
Thank you, but why is it
(-infinity -7)?
is it translated to
negative infinity - 7?
You are right in actual practice, it is normal to exclude infinity or negative infinity. In my books, -infinity is a short form for negative infinity.
So the correct answer would be:
(negative infinity, -7)
Write the interval notation corresponding to the set notation {x | - 5 < x 4}.
To write the interval notation corresponding to the set notation {x | x < -7}, we need to express the values of x in terms of an interval.
In this case, since x is defined as being less than -7, we can represent this interval as (-∞, -7).
Explanation: In interval notation, we use parentheses to indicate that the endpoints are not included in the interval. The symbol -∞ represents negative infinity, indicating that there is no lower limit to the interval. So, (-∞, -7) means that any value of x that is less than -7, but not equal to -7, is included in the set.