Disjoint Subsets, Complement, CardinalityDate: 09/03/97 at 00:59:05 From: Lisa Wang Subject: Sets Problem What does this mean: Sets A, B, and C are DISJOINT subsets of the set U? What does disjoint mean? Please also explain to me other basic sets operations. (e.g. cardinality, complement, etc.) Date: 09/03/97 at 05:44:39 From: Doctor Mitteldorf Subject: Re: Sets Problem Dear Lisa, The word "disjoint" means that there's no overlap between A and B or between B and C or between A and C. They're all completely separate, and have no members in common. The word "cardinality" refers to the number of elements in a set. You just count them up - it's that simple. The word "complement" refers to what's left over after you extract a subset. For example, if U is the set {1 2 3 4 5} and A is the subset {1 2 3} then the complement of A is just the set {4 5} of elements thatare members of U but not members of A. -Doctor Mitteldorf, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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