Differential Equations Review 1. y + 2y = x + e-3x y(0) = 2 2 dx 2x I.F. = e =e 2x 2x e y + 2e y = xe2x + e-x e2x y = xe2x + e-x dx 1 1 1 1 13 e2x y = xe2x - e2x - e-x + c y = x - - e-3x + e-2x 2 4 2 4 4 dy 2. x + y = 2x sin x dx dy 1 + y = 2 sin x dx x 1

Math 391: Methods of Dierential Equations:
Practice for the third midterm
This midterm will primarily cover the following sections:
5.1, 5.2, 5.4, 5.5; 6.1-6.2; 10.1-10.2.
Of course, knowledge of earlier material will be needed on the exam.
The rst three

Math 391: Methods of Dierential Equations:
Practice for the second midterm
This midterm will primarily cover sections 3.5-3.8 and 4.1-4.3, though knowledge of earlier
material will be needed to do these problems.
The following problems were taken from mid

Math 391: Methods of Dierential Equations:
Practice for the second midterm
This midterm will primarily cover sections 3.5-3.8 and 4.1-4.3, though knowledge of earlier
material will be needed to do these problems.
The following problems were taken from mid

Math 391: Methods of Dierential Equations:
Practice for the rst midterm
The rst midterm will cover material up through the end of section 3.4. There will be at
least one word problem and probably also a theoretical problem (as in Quiz 4). I expect to
put