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Learn how to solve linear differential equations using integrating factors and various solution techniques. Includes a review, examples, and tips for quiz grading.
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MAT 3237Differential Equations Section 2.3 Linear Equations http://myhome.spu.edu/lauw
HW • WebAssign 2.3
Reality Check …. • Are you doing your homework ASAP? • Do you have a study group? • Do you write your solutions formally down on a paper/notebook?
Linear (First Order) D.E. Technique: Multiply both side by the integrating factor
1. Verify is the general solutions 2. Q: Why not using ? A: Remarks
Presentation • When there are two groups of related calculations, do not mix them up.
Two-Column • Integration by parts, substitutions, partial fractions, …
Example 2 **Reminder: Tell Wai to specify the interval at the end. He usually does not remember. You can take one point off from him. Ha, ha!
Review: We learned… • how to identify first order linear equations. • how to compute and use the integrating factors to solve linear equations. • we can ignore the integration constant in evaluating the integrating factors, with the understanding that the constant does not affect the solution. • we need to “eliminate” the absolute value in the integrating factor (choose the biggest interval, or other methods*) • not to interrupt the flow of the solutions by using the 2-column presentation.
Quiz Grading - By deduction • Points will be taken off for missing steps or contents. • Points will be taken off for inaccurate information or mistakes. • Points will be taken off for bad notations, missing notations, bad presentations, and “horrible” handwritings. • Correct answer alone is not sufficient. No steps, no points.