HP 50g Graphing Calculator - Manual (Page 389)

Page 12-6
ROOT: 1.6635... The calculator indicated, before showing the root,
that it was found through SIGN REVERSAL. Press L to recover the
menu.
Θ Pressing @ISECT will give you the intersection of the curve with the x-axis,
which is essentially the root. Place the cursor exactly at the root and
press
@ISECT. You will get the same message as before, namely SIGN
REVERSAL, before getting the result I-SECT: 1.6635…. The @ISECT
function is intended to determine the intersection of any two curves
closest to the location of the cursor. In this case, where only one curve,
namely, Y1(X), is involved, the intersection sought is that of f(x) with the
x-axis, however, you must place the cursor right at the root to produce
the same result. Press L to recover the menu.
Θ Place the cursor on the curve at any point and press @SLOPE to get the
value of the slope at that point. For example, at the negative root,
SLOPE: 0.16670…. Press L to recover the menu.
Θ To determine the highest point in the curve, place the cursor near the
vertex and press @EXTR The result is EXTRM: 0.. Press L to recover
the menu.
Θ Other buttons available in the first menu are @AREA to calculate the area
under the curve, and @SHADE to shade an area under the curve. Press
L to see more options. The second menu includes one button called
@VIEW that flashes for a few seconds the equation plotted. Press @VIEW.
Alternatively, you can press the button
@NEXQ (NEXt eQuation) to see the
name of the function Y1(x). Press L to recover the menu.
Θ The button gives the value of f(x) corresponding to the cursor
position. Place the cursor anywhere in the curve and press . The
value will be shown in the lower left corner of the display. Press L
to recover the menu.
Θ Place the cursor in any given point of the trajectory and press TANL to
obtain the equation of the tangent line to the curve at that point. The
equation will be displayed on the lower left corner of the display. Press
L to recover the menu.
Θ If you press the calculator will plot the derivative function, f'(x) =
df/dx, as well as the original function, f(x). Notice that the two curves
intercept at two points. Move the cursor near the left intercept point
and press
@)@FCN! @ISECT, to get I-SECT: (-0.6834…,0.21585). Press L
to recover the menu.
Θ To leave the FCN environment, press @)PICT (or L)PICT).
Θ Press @CANCL to return to the PLOT WINDOW environment. Then, press
L @@@OK@@@ to return to normal calculator display.