Maths: What does \ denote?

[demon8991]

In this set theory example what does the \ denote?

(A x B) \ (A x C)

Im assuming it means minus, therefore if A = {1,2,3,4}, B = {1,5}, and C = {5,8}

Then (A x B) would be {(1,1)(1,5)(2,1)(2,5)(3,1)(3,5)(4,1)(4,5)}

and (A x C) would be {(1,5)(1,8)(2,5)(2,8)(3,5)(3,8)(4,5)(4,8)}

Then assuming i am right on the \ being a minus then (A x B) \ (A x C) = {(1,1)(1,8)(2,1)(2,8)(3,1)(3,8)(4,1)(4,8)}

Am i right by saying this?

 

[wizardmaxx]

Divided by

 

[Brizzles]

Divided by

" / "means divided by

 

[wizardmaxx]

Maybe a typo ?

 

[demon8991]

Hmmm definatly not a typo its been used quite few times.

 

[Drawoh Tesremos]

X \ Y means the set of all objects which are in X but not in Y.

For example, If X is the set of positive even numbers less then 20, and, and Y is the set of integers which are also multiples of 4, then X \ Y is the set {2, 6, 10, 14, 18}

 

[Cybermyk]

Yup \ = Difference of sets

 

[wizardmaxx]

Sorry been out the loop 4 a long time.

 

[demon8991]

X \ Y means the set of all objects which are in X but not in Y.

For example, If X is the set of positive even numbers less then 20, and, and Y is the set of integers which are also multiples of 4, then X \ Y is the set {2, 6, 10, 14, 18}

Then (A x B) would be {(1,1)(1,5)(2,1)(2,5)(3,1)(3,5)(4,1)(4,5)}

and (A x C) would be {(1,5)(1,8)(2,5)(2,8)(3,5)(3,8)(4,5)(4,8)}

Ahhh ok i see so (A x B) \ (A x C) = {(1,1)(2,1)(3,1)(4,1)}

Yer?

 

[Drawoh Tesremos]

Then (A x B) would be {(1,1)(1,5)(2,1)(2,5)(3,1)(3,5)(4,1)(4,5)}

and (A x C) would be {(1,5)(1,8)(2,5)(2,8)(3,5)(3,8)(4,5)(4,8)}

Ahhh ok i see so (A x B) \ (A x C) = {(1,1)(2,1)(3,1)(4,1)}

Yer?

Yes - that looks correct.

 

[demon8991]

Hope so, otherwise i have completly misunderstood everything.