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Lecture 21 – Sequences. A list of numbers following a certain pattern { a n } = a 1 , a 2 , a 3 , a 4 , … , a n , … Pattern is determined by position or by what has come before. 3, 6 , 12 , 24, 48 , …. Defined by n(position).
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Lecture 21 – Sequences A list of numbers following a certain pattern {an} = a1 , a2 , a3 , a4 , … , an , … Pattern is determined by position or by what has come before 3, 6, 12, 24, 48, …
Defined by n(position) Find the first four terms and the 100th term for the following:
Arithmetic Sequence An arithmetic sequence is the following: with a as the first term and d as the common difference.
GeometricSequence A geometric sequence is the following: with a as the first term and r as the common ratio.
Convergence We say the sequence “converges to L” or, if the sequence does not converge, we say the sequence “diverges”. A sequence that is monotonic and bounded converges.
Monotonic and Bounded Monotonic: sequence is non-decreasing (non-increasing) Bounded: there is a lower bound m and upper bound M such that • Monotonic & Bounded: • Monotonic & not Bounded: • Not Monotonic & Bounded: • Not Monotonic & not Bounded:
Example 1 – Converge/Diverge? Example 2 – Converge/Diverge?
Lecture 22 – Sequences & Series Example 3 – Converge/Diverge? Growth Rates of Sequences: q, p > 0 and b > 1
Partial Sums Adding the first n terms of a sequence, the nth partial sum: Series – Infinite Sums If the sequence of partial sums converges, then the series converges.
Find the first 4 partial sums and then the nth partial sum for the sequence defined by: Example 1
The partial sum for a geometric sequence looks like: Geometric Series
Lecture 23 – More Series Find the sum of the geometric series: Geometric Series – Examples
Find the sum of the geometric series: Geometric Series – More Examples