# What does this mean,(A Δ B)^c?

1. Jan 30, 2006

### matrix_204

What does this mean,

(A Δ B)^c? And what does it equal to?

I know that (A Δ B)= (A-B) U (B-A).

2. Jan 30, 2006

### d_leet

Might mean the complement of (A Δ B)

3. Jan 30, 2006

### matrix_204

Yes, I know, but how do I find the complement. Thats where I'm stuck. What is the complement equal to?

4. Jan 30, 2006

### d_leet

I don't really understand what you are asking, the complement is going to be all members of the universe that are not in the given set so from what you have told me it would be the set of all x such that x is not a member of the symmetric difference between A and B.

5. Jan 31, 2006

### matrix_204

So for example, all x such that x is not in (A Δ B)= (A-B) U (B-A)!
What I was asking is what's (A Δ B)^c= ??
Because in the text book it's not given and I got stuck for one of the problems before I could proceed.

6. Jan 31, 2006

### arildno

Note that your triangle thingy set does not contain points common to A and B, nor does it contain points in the complement of the union of A and B.

Does that help?