Math Explanation

[Celundyl]

Ok, first off, I understand all of this, I'm just asking an easy method of how to explain it to others.

My Math teacher (8th grade, Pre-AP) said that the simplest way to write "empty set" was a zero with a slash through it.

I was the only one in the class who understood the difference between 0 and empty set (concept-wise, not written). So naturally, my math teacher wants me to (on Wed.) explain to the class why zero and empty set are two TOTALLY different things.

How can I explain to thick-skulled "Honor" students (honestly, Pre-AP is too easy these days) how empty set and zero are different?

Should I do something like x+2 = x+99 and then have them substitute x with 0 to prove 0 doesnt work?

"God, help me from the land of those with a IQ that doesnt change with exponents."

[Icetetter]

got me there. I'm seventh grade and I understand, but.... how do you teach other?

[Liokae]

There's an easier route: Instead of a slashed zero, just use {}.

[kevinok]

Or the real name for it is null. Who is your teacher because I think I have heard that before.

[Diamond187]

It is used in some lower maths but it's really useless as soon as they start using phi for angles (for obvious reasons). I'm not exactly sure what you mean by empty set, but I think I use the good old "does not exist" or "undefined" abbreviated by DNE or und. respectively.

[Vagrant]

What the hell is an empy set anyways? I'm in Int 3 (Yes, my school's system is screwed)

[Afterburner]

Just say that if the set has the number 0, then it isn't empty. A null set has NOTHING in it.

[Liokae]

A solution set is a set of values that satisfies an equation. (IE, for [x^2 - 1] = 0, the solution set is {-1, 1}). If no values satisfy the equation, then you have an empty set.

[theryman]

lets have the question be x^2<3

The answer set will be {3,7,5,4,2}
none of them are less than 3, so it would be a null set . You would symbolize this by (/). However zero does not work in that set either.

[Liokae]

... an answer set is not a predetermined thing. If you are given an equation, the answer set is *determined* by what satisfies the equation. If nothing satisfies it, *then* you have a null set.

For inequalities, the solution set is given by a range of numbers. The solution set for x^2 - 1 < 0 would be (-1,1), the solution set for x^2 - 1 <= 0 would be [-1,1], and the solution set for x^2 - 1 > 0 is (-infinity, -1)U(1, infinity).

[Celundyl]

thanks everyone, i should do fine....