Differential Equations Project

Computer Lab Modules

 

First Order Linear D. E.'s

 

 

Preliminaries. We wish to solve the first order linear D. E. with a given I. C.
[Graphics:e2.txtgr1.gif],
the integrating factor is [Graphics:e2.txtgr2.gif].

 

Computer Lab Work.

 

Exercise 1. Use Mathematica to solve the first order linear D. E. with the given I. C.
[Graphics:e2.txtgr3.gif]with y(0) = 3.
Plot the solution over the interval [0, 3].

First enter the functions p[x] and q[x] and the initial condition.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr4.gif]

Construct the integrating factor.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr6.gif]

Construct the general solution.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr7.gif]

Solve for the constant c.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr8.gif]

Form the particular solution from the general solution.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr9.gif]

Verify that this is the correct solution to the D. E.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr10.gif]

Verify that it has the correct I. V.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr11.gif]
 

Exercise 2. Use Mathematica to solve the first order linear D. E. with the given I. C.
[Graphics:e2.txtgr12.gif]with y(0) = 1.
Plot the solution over the interval [0, 3].

First enter the functions p[x] and q[x] and the initial condition.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr13.gif]

Construct the integrating factor.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr14.gif]

Construct the general solution.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr15.gif]

Solve for the constant.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr16.gif]

Form the particular solution from the general solution.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr17.gif]

Verify that this is the correct solution to the D. E.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr18.gif]

Verify that it has the correct I. V.

[Graphics:e2.txtgr5.gif][Graphics:e2.txtgr19.gif]
 
 

Solutions.

 

Return to the Differential Equations Project

Return to the Numerical Analysis Project

Return to the Complex Analysis Project

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews, 1998