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#### The Fundamental Theorem of Calculus

Three Different Concepts
The Fundamental Theorem of Calculus (Part 2)
The Fundamental Theorem of Calculus (Part 1)
More FTC 1

#### The Indefinite Integral and the Net Change

Indefinite Integrals and Anti-derivatives
A Table of Common Anti-derivatives
The Net Change Theorem
The NCT and Public Policy

#### Substitution

Substitution for Indefinite Integrals
Examples to Try
Revised Table of Integrals
Substitution for Definite Integrals
Examples

#### Area Between Curves

Computation Using Integration
To Compute a Bulk Quantity
The Area Between Two Curves
Horizontal Slicing
Summary

#### Volumes

Slicing and Dicing Solids
Solids of Revolution 1: Disks
Solids of Revolution 2: Washers
More Practice

#### Integration by Parts

Integration by Parts
Examples
Integration by Parts with a definite integral
Going in Circles

#### Integrals of Trig Functions

Antiderivatives of Basic Trigonometric Functions
Product of Sines and Cosines (mixed even and odd powers or only odd powers)
Product of Sines and Cosines (only even powers)
Product of Secants and Tangents
Other Cases

#### Trig Substitutions

How Trig Substitution Works
Summary of trig substitution options
Examples
Completing the Square

#### Partial Fractions

Introduction
Linear Factors
Improper Rational Functions and Long Division
Summary

#### Strategies of Integration

Substitution
Integration by Parts
Trig Integrals
Trig Substitutions
Partial Fractions

#### Improper Integrals

Type 1 - Improper Integrals with Infinite Intervals of Integration
Type 2 - Improper Integrals with Discontinuous Integrands
Comparison Tests for Convergence

#### Differential Equations

Introduction
Separable Equations
Mixing and Dilution

#### Models of Growth

Exponential Growth and Decay
Logistic Growth

#### Infinite Sequences

Examples of Infinite Sequences
Limit Laws for Sequences
Theorems for and Examples of Computing Limits of Sequences
Monotonic Covergence

#### Infinite Series

Introduction
Geometric Series
Limit Laws for Series
Test for Divergence and Other Theorems
Telescoping Sums and the FTC

#### Integral Test

The Integral Test
Estimates of Value of the Series

#### Comparison Tests

The Basic Comparison Test
The Limit Comparison Test

#### Convergence of Series with Negative Terms

Introduction, Alternating Series,and the AS Test
Absolute Convergence
Rearrangements

The Ratio Test
The Root Test
Examples

#### Strategies for testing Series

Strategy to Test Series and a Review of Tests
Examples, Part 1
Examples, Part 2

#### Power Series

Finding the Interval of Convergence
Power Series Centered at $x=a$

#### Representing Functions as Power Series

Functions as Power Series
Derivatives and Integrals of Power Series
Applications and Examples

#### Taylor and Maclaurin Series

The Formula for Taylor Series
Taylor Series for Common Functions
Adding, Multiplying, and Dividing Power Series
Miscellaneous Useful Facts

#### Applications of Taylor Polynomials

Taylor Polynomials
When Functions Are Equal to Their Taylor Series
When a Function Does Not Equal Its Taylor Series
Other Uses of Taylor Polynomials

#### Partial Derivatives

Visualizing Functions in 3 Dimensions
Definitions and Examples
An Example from DNA
Geometry of Partial Derivatives
Higher Order Derivatives
Differentials and Taylor Expansions

#### Multiple Integrals

Background
What is a Double Integral?
Volumes as Double Integrals

#### Iterated Integrals over Rectangles

How To Compute Iterated Integrals
Examples of Iterated Integrals
Cavalieri's Principle
Fubini's Theorem
Summary and an Important Example

#### Double Integrals over General Regions

Type I and Type II regions
Examples 1-4
Examples 5-7
Order of Integration

### Introduction

With the exceptions of geometric series, where $r$ may be negative, or the rare series with telescoping partial sums, the convergence tests we have worked with so far only work with positive-termed series.  When the terms in a series can be positive or negative, things get more complicated; the sequence {$s_n$} of partial sums may not be monotonic, so it can be bounded yet divergent.  This module will introduce the Alternating Series Test, which works on series in which the terms have alternating signs.

### Alternating Series and the Alternating Series Test

An alternating series is a series $\displaystyle\sum_{n=1}^\infty a_n$ where $a_n$ has alternating signs.  Notice that if $a_n$ has alternating signs, we will be able to let $b_n=\left\vert a_n \right\vert$, and write $a_n=(-1)^n b_n$ or $a_n=(-1)^{n-1}b_n$.  For instance, $$\displaystyle\sum_{n=1}^\infty \frac{(-1)^{n-1}}{n} = 1 - \frac{1}{2} + \frac{1}{3} - \frac 14 + \ldots=\sum_{n=1}^\infty (-1)^{n-1}\frac{1}{n}$$has terms $a_n=\frac{(-1)^{n-1}}{n}$ and $b_n=\frac{1}{n}$.

 Alternating Series Test (AST):  If the alternating series $\displaystyle\sum_{n=1}^\infty (-1)^{n-1}b_n=b_1-b_2+b_3-b_4+\cdots$ satisfies $b_n>0$, $b_{n+1}\le b_n$ for all $n$, and $\displaystyle{\lim_{n \to \infty} b_n = 0}$, then the series converges.

In other words, if the absolute values of the terms of an alternating series are non-increasing and converge to zero, the series converges.

This is easy to test; we like alternating series.  To see how easy the AST is to implement, DO:  Use the AST to see if $\displaystyle\sum_{n=1}^\infty (-1)^{n-1}\frac{1}{n}$ converges.  This series is called the alternating harmonic series.

This is a convergence-only test.
In order to show a series diverges, you must use another test.  The best idea is to first test an alternating series for divergence using the Divergence Test.  If the terms do not converge to zero, you are finished.  If the terms do go to zero, you are very likely to be able to show convergence with the AST.

Warning:  The converse of the AST is not true; we have series that are alternating and convergent and do not satisfy the AST.  For example, if we take the terms of $\sum\frac{1}{n^2}=1+\frac{1}{2}+\tfrac14+\tfrac19+\tfrac1{16}+\tfrac1{25}+\cdots$, and exchange the first two terms, then the second two, etc., and then put in alternating signs, we get $\frac{1}{2}-1+\frac{1}{9}-\frac{1}{4}+\frac{1}{25}-\frac{1}{16}+\cdots$, which does not satisfy the conditions of the AST since $b_{n+1}\le b_n$ does not hold for all $n$.  However, this series is convergent (we will be able to prove its convergence later using the ideas of Absolute Convergence).

The following video will explain how the AST works, give more details on the alternating harmonic series, and look at the values of some interesting alternating series.