HP 39g Graphing Calculator - Manual (Page 93)

3. Use the Plot view to find an initial guess for T. First set
appropriate X and Y ranges in the Plot Setup. Since we
have an equation,X = V xT + Ax T ~ / 2 , the plot will
produce two graphs: one for Y = X and one for
Y = V x T + A x / 2 . Since we have set X = 30 in
this example, one of the graphs will be F = 30 .
Therefore, make the YRNG - 5 to 35. Keep the XKNG
default of -6.5 to 6.5.
\SH\fT ¡SETUP-PLOT
g(G)]5 I ENTER j
35 I ENTER I
4. Plot the graph.
XRNS
VFiNS
KTICK
RES;
»SOLVE PLOT SETUPS
-6.5 6.5
imnai
Detail
ENTER HDRIZDNTRL TICK SPRCINQ
PLOT
5. Move the cursor near the positive (right-side)
intersection. This cursor value will be an initial guess for
T .
[F] to move cursor to
the intersection.
\ /
\
V
y
T;3.H E1;3V I8I3!|I|
The two points of
intersection show that
there are two solutions
for this equation. However, only positive values for .v
make sense, so we want to find the solution for the
intersection on the right side of the y-axis.
6. Return to the Numeric view.
NUM
Note: the T-value is filled
in with the position of the
cursor from the Plot
view.
iSOLVE NUMERIC VIEWS
ENTER VRLOE OR PRESS SOLVE______
7. Ensure that the T value is highlighted, and solve the
equation.
iSOLVE NUMERIC VIEWS
4
ENTER VRLUE OR PRESS SOLVE______
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Solve aplet 7-9