1550078481-Ordinary_Differential_Equations__Roberts_

500 Ordinary Differential Equations

is a single precision, floating-point representation for the number 23400000.
And 314159E-5, 314.159E-02, 0.00314159E+3, and .00314159E3 are all six
digit, single precision, floating-point representations for 1r. If the E's in the
previous sentence are replaced by D's, then we have four double precision
representations for 7r. Single precision constants are stored with seven digits
although only six digits may be accurate. Double precision constants are
stored with seventeen digits but only sixteen digits may be accurate. By
default numbers such as 3456789012 and 456. 7890123 will be stored as double
precision, floating-point constants.

When you double click on the CSODE icon, the screen shown in Figure A.l
appears on your monitor. To select one of the six programs to run, click the
button on the left which contains the name of the program.

iii • Computer Solution of 01dma1y D1ffe1enl1al Equations by Chailes Roberts R~ D

l[ __ ~~~-=~JI Graphs the function y = f(x)

DIAFIELD Graphs the direction field y' = f(x.y)

soLVEIVP Solves the scalar (1 component) initial value problem:

y· = f(x.y): y(c) = d

POLYATS Finds all roots of a polynomial with complex coefficients

EIGEN Computes the eigenvalues and eigenvectors of a real matrix

SOLVE SYS Solves the vector (2-6 component) initial value problem:

y' = f(x.y): y(c) = d

Figure A. l Program Selection Screen

Using POLYRTS

In section 1.2, you were asked if you could solve the polynomial equation

2x^4 - 3x^3 - 13x^2 + 37x - 15 = 0.

In order to use POLYRTS to solve this equation, we double click the CSODE
icon and when the program selection screen (Figure A.l) appears on the mon-
itor, we single click on the POLYRTS button. This causes the screen shown
in Figure A.2 to appear on the monitor.