HP 40gs HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010.p - Page 58

Inter Slope, many other methods of doing this, some of which can be found on s 66

Page 58 highlights

Intersection The next function tool in the menu is Intersection. If you choose this option, then you will be presented with a choice similar to the one in the screen shown right. The Intersection option only appears if there is more than one function in the PLOT view. Exactly what is in the menu depends on how many functions you have showing. In the case shown here we only have two, so the choice is of finding the intersection of F1(X), which is the one the cursor is on, with either the X axis, or the other function F2(X). The results of choosing F2(X) are shown right. Calculator Tip When you find an intersection or a root the value of the x coordinate is stored in the memory X. If you immediately change to the HOME view and type X and hit ENTER then you can retrieve and use this value. See "The Expert" on page 75 for more detail and examples. Slope This gives the numerical value of the derivative at the point of the cursor for the current function. There are many other methods of doing this, some of which can be found on pages 66, 70 & 83. Calculator Tip If the value at which you wish to find the slope is not accessible for the current scale then use the key to jump to the desired point before choosing Slope. The value is remembered and used in the Slope calculation, despite perhaps not being 'on' the current scale. In the same way, choosing Slope immediately after finding a root or intersection will give the slope at the remembered value rather than the nearest dot on the scale. 58

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Intersection
menu is
Intersection
. If you choose
this option, then you will be presented with a choice similar to the one in
the screen shown right.
The
Intersection
option only appears if there is
more than one function in the
PLOT
view.
The next function tool in the
Exactly what is in the menu depends on how many functions you have
showing. In the case shown here we only have two, so the choice is of
finding the intersection of
F1(X)
, which is the one the cursor is on, with
either the X axis, or the other function
F2(X)
. The results of choosing
F2(X)
are shown right.
Calculator Tip
X
HOME
view
and type
X
When you find an intersection or a root the value of the x coordinate is
stored in the memory
. If you immediately change to the
and hit
ENTER
then you can retrieve and use this value.
See “The Expert” on page 75 for more detail and examples.
Slope
This gives the numerical value of the derivative at the point of the cursor for the current function.
There are
many other methods of doing this, some of which can be found on pages 66, 70 & 83.
Calculator Tip
Slope
.
Slope
l
In the
Slope
nearest dot on the scale.
If the value at which you wish to find the slope is not accessible for the
current scale then use the
key to jump to the desired point before
choosing
The value is remembered and used in the
calcu ation, despite perhaps not being ‘on’ the current scale.
same way, choosing
immediately after finding a root or
intersection will give the slope at the remembered value rather than the
58