# Math 218 Section 3 Fall 2019

#### General

Rabinoffice Hours will be held Mondays, 3–4pm and Fridays, 1–3pm, in my office, Math & Physics 243. Please come! If you can't make it, please email me!

#### Homework

All page and question numbers refer to Strang, 5th edition. Homework is due on Gradescope by the beginning of class on the day listed.

Week Due Date Problems Solutions
1Tuesday, September 3Homework #1Solutions
2Tuesday, September 10Homework #2Solutions
3Tuesday, September 17Homework #3Solutions
4Tuesday, September 24Homework #4Solutions
5Tuesday, September 24Homework #5Solutions
6Thursday, October 10Homework #6Solutions
7Tuesday, October 15Homework #7Solutions
8Tuesday, October 22Homework #8Solutions
9Tuesday, October 29Homework #9Solutions
10Tuesday, November 5Homework #10Solutions
11Tuesday, November 12Homework #11Solutions
12Tuesday, November 19Homework #12Solutions
13Thursday, November 28Homework #13Solutions
14Thursday, December 5Homework #14

#### Exams

Each midterm exam covers all material up through the previous homework assignment. Midterms focus on the material covered after the previous exam, but due to the cumulative nature of the material, topics from previous exams will also appear.

The final exam will cover all course materials, except those specifically excluded in class.

Date Practice Exam Solutions
Thursday, September 26Practice Test #1Midterm #1Solutions
Thursday, October 24Practice Test #2Midterm #2Solutions
Thursday, December 5Practice Test #3Midterm #3Solutions
Saturday, December 14, 2–5pmPractice Problems and Answers

#### Daily

Date Materials
8/27 Demo: A vector by coordinates
Demo: Scalar multiplication
Demo: Vector subtraction
Demo: Linear combinations of two vectors in the plane
Demo: Linear combinations of two vectors in space
Demo: Linear combinations of three vectors in space
8/29 Demo: A plane in space
Demo: Two planes intersecting in space
Demo: Column picture of two equations in two variables
Demo: Column picture of two equations in three variables
Demo: Column picture of three equations in three variables
9/3 Demo: Column picture of an inconsistent system of three equations in two variables
Demo: Column picture of a consistent system of three equations in two variables
9/5 Slideshow: Gauss–Jordan Elimination
Rabinoff's Reliable Row Reducer
9/7 Demo: A subspace of R3
Demo: A span in R2
Demo: A span in R2
Demo: A span in R2
Demo: A span in R3
Demo: Column space of an inconsistent system of three equations in two variables
Demo: Column space of a consistent system of three equations in two variables
9/19 Demo: Span of one vector in the plane
Demo: Span of two vectors in the plane
Demo: Span of three vectors in the plane
Demo: Span of one vector in space
Demo: Span of two vectors in space
Demo: Span of three vectors in space
Demo: Parameterized line
Demo: Parameterized plane
9/24 Demo: Solution set of two equations in three variables
Demo: Solution set of three equations in three variables
Demo: Solution set of three equations in two variables
Demo: Solution set of two equations in three variables
10/1 Demo: Linear independence of two vectors in the plane
Demo: Linear dependence of three vectors in the plane
Demo: Linear independence of two vectors in space
Demo: Linear independence of three vectors in space
10/10 Demo: Orthogonal complements in the plane
Demo: Orthogonal complements in space
Demo: Orthogonal complements in space (2)
Demo: Orthogonal projection onto a line in the plane
Demo: Orthogonal projection onto a line in space
Demo: Orthogonal projection onto a plane in space
10/17 Demo: Least-squares approximation
Demo: Best-fit line
Demo: Best-fit parabola
Resource: See my textbook for other examples.
10/29 Demo: Eigenvectors of a scaling matrix
Demo: Eigenvectors of a dilation matrix
Demo: Eigenvectors of a projection matrix
Demo: Eigenvectors of a reflection matrix
Demo: Eigenvectors of a rotation matrix
Demo: Eigenvectors of a shear matrix
10/31 Demo: Eigenspaces of a 2x2 matrix
Demo: Eigenspaces of a 3x3 matrix
Demo: Rabbits multiply
11/7 Demo: Dynamics of a diagonal 2x2 matrix
Demo: Dynamics of a diagonal 2x2 matrix
Demo: Dynamics of a diagonal 3x3 matrix
Demo: Geometry of a diagonalizable 2x2 matrix
Demo: Dynamics of a diagonalizable 2x2 matrix
Demo: Geometry of a diagonalizable 2x2 matrix
Demo: Dynamics of a diagonalizable 2x2 matrix
Demo: Dynamics of a diagonalizable 3x3 matrix
11/27 Class notes: L24