Ok, I received some help earlier.
I'm hoping for some kind souls to help again.
Now I'm completely lost on a problem.
Solve and Express in interval notation.
1<=|x|<=4
I came up with this
-4<=x<=4 and x<=-1 and 1<=x
the book says it is
[-4,-1]U[1,4]
I know what interval notation is, but I'm lost on the how they grouped the different x values.
What step am I missing to get the books answer?
[edit1]
Do we default grouping the negative values together and the positive values together?
I'm not sure, but let me try to explain why I see it grouping in this way.
-4 is less then or equal to x which is less then or equal to 4
this covers all values from -4 to 4
x is also less then or equal to -1
x is greater than or equal to 1
-4 to 4 is my outside boundries
so
-4 to -1 is one of the boundries
1 to 4 is the upper side boundry.
Is this the way they are looking at it or is there a fail safe rule that I can use?
[/edit1]
