MATH 120 Lecture 12: Chapter 7.1 Sets and Notation
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Professor brendan sheehan chapter 7. 1 sets and set notation. Is the "is an element of" symbol. 9 a is read as "9 is an element of the set a" 2 d is read as "2 is not an element of the set d" The null set is a set with no elements, indicated by this symbol: . A = {0} has 1 element, which is 0. B = {} has no elements, so b . Subsets are basically sets within sets, indicated by or . B is a subset of a because all the elements in b are also in a. B a = b is a subset of a n(x) is the symbol for the # of elements in a. A = {5, 7, 9} n(a) = 3, since there are 3 elements in a. 2 , which will form that many subsets, with k as the number of elements.
