# Announcements

• Final grades have been submitted to the registrar. They should appear on Dal Online shortly.

# Course Outline

This is a seven week course starting May 12th and ending June 27th. Classes are Monday and Thursday evenings from 6pm to 8:45pm and are held in LSC 216, which is around the corner from the life sciences museum.

The textbook for this course is Linear Algebra: A Modern Introduction (2nd edition) by David Poole and I will be following it fairly closely. As an additional reference (or alternative reference as your finances permit), I am providing a digital copy of Linear Algebra by Jim Hefferon. This book is free and open source, but it takes a different approach than Poole. Also, note that the second course in linear algebra, Math 2040, will be using questions taken directly from Poole.

# Instructor

• Andrew Hoefel
• Email:
• Office: Chase 311
• Office Hours: Tuesday, Wednesday, Friday, 10:30 to 11:30.

# Examinations

• Test 1:   1.5 hours, Thursday May 29th, in class. Outline, Solution.
• Test 2:   1.5 hours, Thursday June 12th in class. Outline, Solution.
• Final Exam:   3 hours, June 26th from 6pm to 9pm. Location: LSC 206 (down the hall from our regular classroom). Outline.

# Marks

Assignment and test marks have been posted. Please email me or talk to me if they have been added or recorded incorrectly. The last three digits of your banner id are used to identify you. If you perfer not to have your marks posted in this way, email me; I am happy to accommodate.

# Assignments

• Assignment 1 was due Thursday May 15. Solution.
• A note on orthogonality: Two vectors are orthogonal if the angle between them is pi/2 (or 90 degrees). From the formula for computing angles, you will see that two vectors u and v are orthogonal exactly when u * v = 0. This observation is needed for questions 4 and 5.
• Assignment 2 was due Thursday May 22. Solution.
• Comments:
• Q2B, the normal of P can be read from the generic equation; the equation was 3x+2y-z=5, so the normal is (3,2,-1). Some people used a cross product of AB and AC to find the normal. That approach works, but it is easier to read it from the generic equation.
• There were many ways to solve Q3 and Q4. In addition to the solutions provided, Q3 can be solved by back substitution on the single equation 2x+3y=4, and Q4 can be solved by writing out the equations x=2+t and y=3-t and solving to eliminate t.
• In Q6, the only real mistakes made were in the arithmetic. Remember to be careful with your signs and take it slowly.
• Assignment 3 due Thursday May 29. Solution.
• Comments:
• Many people performed row operations on the question that asked you to determine the type of solution set by inspection. Your answers were correct, of course, but I'd like you to be able to see ahead of time why a particular system will be inconsistent or consistent, or have a unique solution or infinitely many. Explanations are in the solutions.
• Well done on the row reduction. Most people did this well.
• Assignment 4 due Thursday June 5. Solution.
• Comments:
• To find the inverse of an elementary matrix, apply the reversing row operation to the identity matrix. That is, if the row operation was scaling row i by scalar k, then the reverse is scaling row i by 1/k. If the operation is scaling row i by k and then adding it to row j, then the reverse is adding -k row i to row j. You don't need to rely on the formula for 2x2 inverses.
• Assignment 5 due Thursday June 12. Solution.
• Assignment 6 due Thursday June 19. Solution.
• The errors in Q3e and Q3k have been fixed. Sorry for the inconvenience.
• Assignment 7 due Monday June 23. Solution.
• Since the material was not covered in class, you do not have to do question 4.