Calculator User Manual

Differential Equation Graphing 428
Example
ExampleExample
Example
1. Press 3 and set
Graph=DIFF EQUATIONS.
2. Define a system of equations for the 2nd-
order equation.
Rewrite the equation and make the
necessary substitutions.
3. In the Y= Editor (8#), enter the
system of equations.
4. Enter the initial conditions:
yi1=0 and yi2=1
Note:
t0 is the time at which the initial
conditions occur. It is also the first t
evaluated for the graph. By default,
t0=0.
5. Press:
,
9
— or —
@8Í and set
Axes = ON, Labels =
OFF
, Solution Method = RK, and
Fields = DIRFLD.
Important: For 2nd-order equations, you
must set
Fields=DIRFLD or FLDOFF.
y'' + y = 0
y'' = Ly
y'' =
Ly1
y2' =
Ly1
yi1 is the initial
condition for y(0).
yi2 is the initial
condition for y'(0).