Hello, dear friend, you can consult us at any time if you have any questions, add WeChat: daixieit

Mathematics 376: Ordinary Differential Equations

Assignment 4

Note: This assignment consists of 10 problems of equal weight.

Due: After unit 15

1.    Given that x + 2 is a solution to the homogeneous part of the equation

xg、、- (x + 2)g+ g = 2x3 ec ,  0 < x,

ind the general solution to the equation as a whole.

2.    Reduce the order of the following differential equation and solve

2x2z、、、xz、、- 3z ,  x  0.

3.    Find at least the irst four nonzero terms in a power series expansion of the solution to the IVP

g、、- gsin x - g = Cos x,  g (π) = 0,  g(π) = 1.

4.    Find theirst four nonzero terms in a power series expansion about x = 0 for each of two linearly

independent solutions and the particular solution to

g、、- (x + 1)g = 1.

Then compile the general solution.

5.    For the equation given below, classify all singular points as regular or irregular. For those that are   regular, compile indicial equations, ind roots, and write theoretic forms of theirstand the second

series solutions to the equations. [It is not necessary to solve the equations.]

(x3 - 5x2 + 6x)g、、+ 3  - 2 g = 0.

6.    Find all terms of both linearly independent solutions to the equation

2x(x - 1)g、、- (3x + 1)g+ 2g = 0

by the series method at point x = 0.

7.    Given theirst linearly independent solution g1 (x) = x and the point of expansion x0  = 0, ind the second linearly independent solution g2 (x) to the equation

x (x + 1)g、、xg- g = 0

by the method ofFrobenius.

8.    Given the autonomous system

dx  = x   dg  = x2 + g

a.    ind the critical points.

b.    solve the phase plane equation and classify the critical points, analyzing trajectories of the system.

c.    ind the general solution to the system and determine its stability, analyzing integral curves of the system.

9.    For each of the linear systems given below, ind all the critical points in the plane, and analyze the stability of each point.

a.     d(d)t(x) = x - 1,   dt(dg) = 2x + g + 1.

b.     d(d)t(x) = x + 2g,   dt(dg) = 2x + 5g - 2.

10.  Determine the type and stability of the critical points of the following autonomous system:

dt = x  - 1,   dt  = 2 - 2x - g  .