HP 48g Graphing Calculator - Manual (Page 228)

19
F I N A L S
Contains the independent variable’s final value, ¿ final -
You are trying to solve ?/(tFlNAL) = (some unknown).
Specifies the solution variable. (Defaults to Y.)
Contains the solution variable’s initial value (;^o = y{io))-
,s Contains the solution variable’s final value. This is what
you are trying to solve. You cannot enter a value in this
field.
Contains the acceptable level of absolute error. In a
physical model, select the tolerance to suit the accuracy of
the data, (Defaults to 0.0001.)
Contains the initial step size used to compute the solution.
The calculator uses the Runge-Kutta-Fehlberg method to
calculate
i / final - This method computes its solution by
automatically stepping from point to point, maintaining
accuracy at each point.
F'!: Selects the stiff solver.
Lets you edit a field.
C H O U S
Lets you select a variable.
I
H
I
T+ Replaces the initial values with current final values. Use
this to compute the solution at another point using the
current solution as a starting point.
SOLVE Solve the differential equation.
Solving a Standard Initial-Value Problem
Standard initial-value problems are differential equations that don’t
require the STIFF solver. To determine how stiff a differential
equation is, try graphing it before solving it. Very slow graphing may
indicate that the equation is stiff and the stiff solver should be used.
1. Enter an equation or press C - 0 0 S to select an equation.
2. Specify the independent variable.
3. Enter the initial value for the independent variable.
4. Enter the final value for the independent variable.
5. Specify the solution variable.
19-2 Differential Equations