HP 39g+ User Manual
Page 92
7-8
Solve aplet
where X is distance, V
0
is initial velocity, T is time, and A
is acceleration. This is actually two equations, Y = X and
Y = V
0
T + (AT
2
) / 2.
Since this equation is quadratic for T, there can be both
a positive and a negative solution. However, we are
concerned only with positive solutions, since only positive
distance makes sense.
1. Select the Solve aplet and enter the equation.
Select Solve
X
V
T
A
T
2
2. Find the solution for T (time) when X=30, V=2, and
A=4. Enter the values for X, V, and A; then highlight
the independent variable, T.
30
2
4
to highlight T
3. Use the Plot view to find an initial guess for T. First set
appropriate X and Y ranges in the Plot Setup. With
equation X = V x T + A x T
2
/2, the plot will produce
two graphs: one for
and one for
X = V x T + A x T
2
/2. Since we have set
in
this example, one of the graphs will be
.
Therefore, make the YRNG –5 to 35. Keep the XRNG
default of – 6.5 to 6.5.
SETUP
-
PLOT
5
35
4. Plot the graph.
Y
X
=
X
30
=
Y
30
=