Question

Sets A and I are defined as follows. A = { − 1 , 0 , 1 , 2 , 4 , 6 , 7 } I = { − 2 , − 1 , 1 , 2 , 8 } Find the intersection of A and I

Answer 1

Answer:   {-1, 1, 2}

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Explanation:

Start with set A and circle any value that you find in set I. Those values are  -1, 1, and 2. These elements are found in both sets at the same time, hence they are in the intersection of set A and set I

Refer to the Venn diagram below. We have the values -1, 1, and 2 in the blue overlapped region. A value like 4 is only found in set A, so it's inside circle A, but outside circle I. On the flip side, a value like 8 is found outside of circle A but inside circle I.

The use of curly braces in the answer tells the reader we're dealing with a set of values. The order doesn't matter for any given set. Often it's helpful to put it in order from smallest to largest.