NUMBER OPERATIONS AND CONCEPTS
- Exponential Growth
If r is the ratio between consecutive terms, a 1 is the first term, an is the nth term, and Sn is the sum of the first n terms, then an =
a 1 r n-^1 and
- Union and Intersection of Sets
The things in a set are called elements or members. The union of Set A and Set B, sometimes expressed as A ⋃ B, is the set of
elements that are in either or both of Set A and Set B. If Set A = {1, 2, 3} and Set B = {3, 4, 5}, then A ⋃ B = {1, 2, 3, 4, 5}. The
intersection of Set A and Set B, sometimes expressed as A ∩ B , is the set of elements common to both Set A and Set B. If Set A = {1,
2, 3} and Set B = {3, 4, 5}, then A ∩ B = {3}.