PDA

View Full Version : Algebra help! Interval notations


Johnyi
Jan22-12, 08:15 PM
1. The problem statement, all variables and given/known data

State the meaning of {x:-4<x≤10} in words. Express the set {x:-4<x≤10} using interval notation and draw it on a number line.

2. Relevant equations



3. The attempt at a solution

My attempt. The meaning of {x:-4<x≤10} is that all the numbers of X, are greater than -4, and less than or equal to 10?

Interval notation of {x:-4<x≤10} = (-4,10]


Number line = -----(-4-----------0-----------------------10]

Mark44
Jan22-12, 08:27 PM
Looks fine.

Johnyi
Jan22-12, 08:28 PM
Is my meaning of {x:-4<x≤10} correct?

genericusrnme
Jan22-12, 08:40 PM
yes

(doesn't include
[does include

I like to think of it like the tops of the brackets are edging towards, but not reaching with the (, just like the set is edging towards but not reaching
With the square bracket you have it all there and it has reached there, just like the set

It sounds silly in words but that's how I remembered which meant what