I am a former mathematics instructor at Madison Area Technical College
in Madison, Wisconsin
USA: 1701 Wright Street, Madison, WI
53704 ; Email alehnen@madisoncollege.edu
or aplehnen@execpc.com
The graphic above was generated as a parametric surface using the Java
Program CalcPlot3D,
authored by Professor Paul Seeburger
of Monroe Community College in Brighton,
New York.
The
Axioms of Humility: 
A. Just
because I don't understand an idea, doesn’t mean
that it is wrong. 
B. Just because
I do understand an idea, doesn’t mean that it is right. 
Math Club Presentation: Friday 10/02/2020 
Fall 2019 WisMATYC Presentation 
Winplot Links 
Links to Math Websites including Online Tutorials 
Solving
the Cubic Equation an
Excel file using Cardano's Method to find all roots of any cubic
equation with real coefficients. 
Integration by the Method of Substitution 
Checking Indefinite Integrals by Numerical Quadrature 
The Sum of the Alternating Harmonic Series 
Derivation of the Taylor Series 
Examples of the Gradient 

As of January 2021 Madison College
has removed the files from the facutly server that I maintained before my
retirement. I still have the source files on my home computer. If you wish to access files from any of the following, feel free to email me. 
Courses: 
Calculus
1 Spring 2019 
Calculus
2 Spring 2019 
Calculus
3 Fall 2018 
Introduction
to Engineering Statistics Fall 2018 
Linear
Algebra Spring 2014 
Intermediate
Algebra Fall 2018 
College
Algebra Spring 2018 
Trigonometry
Spring 2019 
Technical
Math 1 Fall 2018 
Technical
Math 2 Spring 2019 
College
Math Fall 2016 
Vocational
Math Fall 2014 
Machine
Tool Math 2 Spring 2015 
Notes on
Logic and Set Theory 
Text
Book (PDF Version) for Introduction to
College Math (804107)

Text
Book (PDF Version)for Vocational Math
(804379) 

Conference
Presentations: 
The Number of Symmetric Permutation Matrices : Presented at the Fall 2013 WisMATYC Conference at Waukesha County Technical College 
Some Different Perspectives on Linear Least Squares: Presented at the Fall 2012 WisMATYC Conference at UW Manitowoc 
Singular Values and Elliptic Orbits of First Oder Linear Differential Systems in 2D: Presented at the MAA Wisconsin 2012 Spring Conference at Milwaukee School of Engineering 
Some Elementary Results Discovered Preparing to Teach Linear Algebra: Presented at the Fall 2010 WisMATYC Conference at UW Marathon County 
The Logistic Equation with a Harvesting Term: Presented at the Fall 2009 WisMATYC Conference at MATC 
A Deranged Experiment by Euler and Bernoulli: Presented at the Fall 2008 WisMATYC Conference at UW Sheboygan County 
The Brachistochrone: A Timely Consideration: Presented in July 2008 at the MAA MathFest in Madison 
Roofing Applications in Trigonometry: Presented at the Fall 2007 WisMATYC Conference at Fox Valley Technical College 
The The Golden Triangle and Mathematical Black Magic of the Pentagram A Play in Four Acts: Presented at the Fall 2006 Fall WisMATYC Conference at UWMarshfield 
Moments of the Distance from the Force Center in a TwoBody Kepler Orbit (Or "Just How Far Away is the Sun Anyway?"): Presented at the MAA Wisconsin 2004 Spring Conference at UW Platteville 
The Sphere Game: A Presentation Made at The Spring 2002 Meeting of the Wisconsin Section of the MAA 