## Math review

Math review Arithmetic sequence The notation of an arithmetic sequence is: where an is the nth term of the sequence and d is the difference between consecutive terms. In order to find the sum of the first n terms, simply find the value of the average term and then multiply that average by the number of terms you are summing. Geometric sequence Whereas in an arithmetic sequence the difference between consecutive terms is always constant, in a geometric sequence the quotient of consecutive terms is always constant. To find the nth term of a geometric sequence, use the following formula: To find the sum of the first n terms of a geometric sequence, use the following formula: where ?1 < r < 1. The Powers of i