2.3soln

# 2.3soln - Solutions to problems from section 2.3 7 0 4 4 Is...

This preview shows pages 1–2. Sign up to view the full content.

Solutions to problems from section 2.3 4. Is the matrix 7 0 4 3 0 1 2 0 9 invertible? Solution: NO. The columns of the matrix above are linearly dependent, for 0 0 0 = 0 7 3 2 + 0 0 0 + 0 4 1 9 . Thus by the inverse matrix theorem (parts (e) and (a)) we know the matrix is singular. 6. Is the matrix 1 5 4 0 3 4 3 6 0 invertible? Solution: NO. Notice 1 5 4 0 3 4 3 6 0 NR 3 = R 3 +3 R 1 −→ 1 5 4 0 3 4 0 9 12 NR 3 = R 3 +3 R 2 −→ 1 5 4 0 3 4 0 0 0 Since the matrix has only 2 pivot positions we know the matrix is singular (by the IMT parts (c) and (a)). 8. Is the matrix 1 3 7 4 0 5 9 6 0 0 2 8 0 0 0 10 invertible? Solution: YES. There are 4 pivot positions, so by the IMT (parts (c) and (a)) we know the matrix above is invertible. 12. Assume all matrices in this problem are n × n matrices. True or false? Justify your answers.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern