On 9/21/99, taylorwh asks about Q12 of MA322-005,Section 5.1 (Sept 23): can you go over this in class? Response: Note that the matrix is a 3 by 3 with first row 5 3 0 second row 0 0 0 and 3rd row 10 6 0 so it is a singular matrix. Which of the properties 4 to 7 (in the book) apply here?

On 9/21/99, taylorwh asks about Q7 of MA322-005,Section 5.1 (Sept 23): can you go over this one in class also? Response: Use property 3 five times to get the answer.

On 9/21/99, taylorwh asks about Q9 of MA322-005,Section 5.1 (Sept 23): can you discuss this one also in class? Response: Yes.

On 9/21/99, claybomi asks about Q10 of MA322-005,Section 5.1 (Sept 23): How can this be false? Response: Ax = O has a unique solution only when A is invertible only when det(A) is not 0.

On 9/21/99, claybomi asks about Q12 of MA322-005,Section 5.1 (Sept 23): I don't understand! Response: check out the hint I gave above. We will discuss this in class.

On 9/21/99, claybomi asks about Q13 of MA322-005,Section 5.1 (Sept 23): Please explain this in class. Response: The real difficulty with this question is the definition of rank 1 matrix. It is defined in chapter 3, which we have not covered (sorry about that). One definition for rank 1 is that all rows are scalar multiples of some row. Work out the answer using this definition.

On 9/21/99, claybomi asks about Q15 of MA322-005,Section 5.1 (Sept 23): Why is this not 8000???? Response: Because the determinant of B^2 is 400.

On 9/21/99, downeyad asks about Q13 of MA322-005,Section 5.1 (Sept 23): What is a rank 1 matrix? Response: See the above response to claybomi.

On 9/21/99, downeyad asks about Q5 of MA322-005,Section 5.1 (Sept 23): I don't follow how you derive that rule from those two properties. Response: We can talk about this in class. If a matrix has a row of 0's then you can multiply by an elimination matrix and get a mtrix with 2 equal rows.