User manual - Chapter 3 Differential Equations

20010101

3-1-1

Using the DIFF EQ Mode

3-1 Using the DIFF EQ Mode

You can solve differential equations numerically and graph the solutions. The general

procedure for solving a differential equation is described below.

Set Up

1. From the Main Menu, enter the DIFF EQ Mode.

Execution

2. Select the differential equation type.

• 1(1st)........ Four types of first order differential equations

• 2(2nd) ...... Second order linear differential equations

• 3(N-th)...... Differential equations of the first order through ninth order

• 4(SYS) ..... System of the first order differential equations

• 5(RCL) ..... Displays a screen for recalling a previous differential equation.

•With 1(1st), you need to make further selections of differential equation type. See

“Differential equations of the first order” for more information.

•With 3(N-th), you also need to specify the order of the differential equation, from 1

to 9.

•With 4(SYS), you also need to specify the number of unknowns, from 1 to 9.

3. Enter the differential equation.

4. Specify the initial values.

5. Press 5(SET) and select b(Param) to display the Parameter screen. Specify the

calculation range. Make the parameter settings you want.

• h................... Step size for the classical Runge-Kutta method (fourth order)

•Step ............. Number of steps for graphing*

and storing data in LIST.

•SF................ The number of slope field columns displayed on the screen (0 – 100).

The slope fields can be displayed only for differential equations of the

first order.

When graphed for the first time, a function is

always graphed with every step. When the

function is graphed again, however, it is

graphed according to a value of Step. For

example, when Step is set to 2, the function is

graphed with every two steps.