HP 49g+ - Manual (Page 387)

Page 12-10
Note: When you press J , your variables list will show new variables
called
@@@X@@ and @@Y1@@ . Press ‚@@Y1@@ to see the contents of this
variable. You will get the program << → X ‘LN(X)’ >> , which you will
recognize as the program that may result from defining the function ‘Y1(X) =
LN(X)’ by using
„à. This is basically what happens when you @@ADD@! a
function in the PLOT – FUNCTION window (the window that results from
pressing
ñ, simultaneously if in RPN mode), i.e., the function gets
defined and added to your variable list.
Next, press
‚@@@X@@@ to see the contents of this variable. A value of 10.275 is
placed in the stack. This value is determined by our selection for the
horizontal display range. We selected a range between -1 and 10 for X. To
produce the graph, the calculator generates values between the range limits
using a constant increment, and storing the values generated, one at a time,
in the variable
@@@X@@@ as the graph is drawn. For the horizontal range ( –1,10),
the increment used seems to be 0.275. When the value of X becomes larger
than the maximum value in the range (in this case, when X = 10.275), the
drawing of the graph stops. The last value of X for the graphic under
consideration is kept in variable X. Delete X and Y1 before continuing.
Graph of the exponential function
First, load the function exp(X), by pressing, simultaneously if in RPN mode, the
left-shift key
„ and the ñ (V) key to access the PLOT-FUNCTION
window. Press @@DEL@@ to remove the function LN(X), if you didn’t delete Y1 as
suggested in the previous note. Press @@ADD@! and type „¸~x` to
enter EXP(X) and return to the PLOT-FUNCTION window. Press L@@@OK@@@ to
return to normal calculator display.
Next, press, simultaneously if in RPN mode, the left-shift key
„ and the
ò (B) key to produce the PLOT WINDOW - FUNCTION window.
Change the H-View values to read: H-View: -8 2
by using 8\@@@OK@@ @2@@@OK@@@. Next, press @AUTO. After the vertical range
is calculated, press @ERASE @DRAW to plot the exponential function.