19 to solve a stiff initial-value problem, Solving a stiff initial-value problem -3 – HP 48g Graphing Calculator User Manual
Page 230
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3. Highlight
and press
SDLVE V'(TJ=Fa,VJi
F:
iF4V:
iF*T:
INDEP: X
INIT: 0
FINAL:6.5
SDLN: Y
INIT: 0
FINAL:
TDL:.0001 iTEP: Df It ISTIFF
CALCULATE ;TIFF DIFFERENTIALi
iaMBBBiKiig;i5imaiiii!!iiiaHTOn
This screen contains the following additional fields:
¿FdV» The partial derivative with respect to y of the expression
in Fi!.
cil-d
The partial derivative with respect to i of the expression
in F s.
19 To solve a stiff initial-value problem:
1. Highlight STIFF and press scCHK .
2. Enter an equation or press CHOOS to select an equation already
stored in memory.
3. Enter the partial derivatives of the equation with respect to y and
t (or press CHOOS to select them if they are stored in memory).
4. Specify the independent variable.
5. Enter the initial value for the independent variable.
(5. Enter the final value for the independent variable.
7. Specify the solution variable.
8
. Enter the initial value for the solution variable.
9. Enter an acceptable error tolerance.
10. (Optional:) Enter a step size. It is usually best to accept the
computed default step size.
11. Press SOLVE.
Example;
Solve this equation for j/(l) given that y{Q)
=
1:
y' =
—1000
*{y — sin{t)) + cos{t)
This example assumes that the calculator is set to radians.
19-4 Differential Equations