HP 40gs User Manual page 94

hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM
7-8
where X is distance, V is initial velocity, T is time, and A
0
is acceleration. This is actually two equations, Y = X and
2
Y = V T + (AT ) / 2.
0
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. 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
two graphs: one for
2
X = V x T + A x T /2. Since we have set
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.
2
2
/2, the plot will produce
Y = X
and one for
X =
Y = 30
Solve aplet
30
in
.