# CDS 140a Winter 2011 Homework 1

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R. Murray, G. Buzi | Issued: 4 Jan 2011 |

ACM 101/AM 125a/CDS 140a, Winter 2011 | Due: 11 Jan 2011 |

**Note:** In the upper left hand corner of the *second* page of your homework set, please put the number of hours that you spent on
this homework set (including reading).

- Perko, Section 1.1, Exercise 3
- Perko, Section 1.1, Exercise 6
- Perko, Section 1.2, Exercise 2
- Perko, Section 1.3, Exercise 5, parts a, c, e
- Perko, Section 1.3, Exercise 6 (for part a, use 5a, 5c, 5e)
- Perko, Section 1.4, Exercise 4
- Perko, Section 1.4, Exercise 6
- Perko, Section 1.5, Exercise 4
- Perko, Section 1.5, Exercise 9
- Perko, Section 1.6, Exercise 2

There are a number of problems that can be solved using MATLAB. If you just give the answer with no explanation (or say "via MATLAB"), the TAs will take off points. Instead, you should show how the solutions can be worked out by hand, along the lines of what is done in the text book. It is fine to check everything with MATLAB.

- For numerical calculations, it is OK to use MATLAB to invert a matrix. But you should not use it to compute the matrix exponential and just put down the answer. Instead, show how to get the matrix exponential into a form in which the calculation can be done by hand (similar to what was done in lecture on 6 Jan) and then carry out the computation.
- For phase portraits, you should generate the diagram by hand and make sure to label any important features. Describe why the portrait looks as it does based on the relevant properties of the dynamical system (eg, eigenvalues of the A matrix).
- For the final exam, you will
*not*be allowed to use MATLAB, so make sure you understand what you are computing and drawing!