Intersection; Slope - HP 39g Master Manual

Intersection

The next function tool in the
Intersection. If you choose this option, then
you will be presented with a choice similar to
the one in the screen shown right.
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.

Slope

This gives the numerical value of the derivative at the point of the cursor for
the current function.
menu is
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 "Tips and Tricks -
Function" on page 83 for more detail and examples.
Calculator Tip
If the value at which you wish to find the slope is not
accessible for the current scale then you will need to use
the key to jump to the desired point before choosing
Slope. The value is remembered and used in the Slope
calculation, despite 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.
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