HP 50g Graphing Calculator - Manual (Page 406)

Page 12-23
which involve constant values x
0
, y
0
, v
0
, and θ
0
, we need to store the values of
those parameters in variables. To develop this example, create a sub-directory
called ‘PROJM’ for PROJectile Motion, and within that sub-directory store the
following variables: X0 = 0, Y0 = 10, V0 = 10 ,
θ0 = 30, and g = 9.806.
Make sure that the calculator’s angle measure is set to DEG. Next, define the
functions (use „à):
X(t) = X0 + V0*COS( θ0)*t
Y(t) = Y0 + V0*SIN( θ0)*t – 0.5*g*t^2
which will add the variables @@@Y@@@ and @@@X@@@ to the soft menu key labels.
To produce the graph itself, follow these steps:
Θ Press „ô, simultaneously if in RPN mode, to access to the PLOT SETUP
window.
Θ Change
TYPE
to
Parametric
, by pressing @CHOOS ˜˜@@@OK@@@.
Θ Press ˜ and type ‘X(t) + i*Y(t)’ @@@OK@@@ to define the parametric plot as that
of a complex variable. (The real and imaginary parts of the complex
variable correspond to the x- and y-coordinates of the curve.)
Θ The cursor is now in the
Indep
field. Press ³~„t @@@OK@@@ to
change the independent variable to t.
Θ Press L@@@OK@@@ to return to normal calculator display.
Θ Press „ò, simultaneously if in RPN mode, to access the PLOT window
(in this case it will be called PLOT –PARAMETRIC window). Instead of
modifying the horizontal and vertical views first, as done for other types of
plot, we will set the lower and upper values of the independent variable
first as follows:
Θ Select the
Indep Low
field by pressing ˜˜. Change this value to
0@@@OK@@@. Then, change the value of
High
to 2 @@@OK@@@. Enter 0.
1@@@OK@@@ for the
Step
value (i.e., step = 0.1).