Symb Mode - HP 39g Master Manual

As can be seen in the screen shots right, the
bottom half of the screen shows the roots (if
any), the value of the discriminant and the
2
equation in the form y=ax
+bx+c.
The key labeled changes the 'step size' of the movements on the
screen. Possible values for the increment are 0.5, 1 and 2.
Pressing SYMB on the calculator, or the screen
key labeled will change the emphasis
from the graph to the equation in the right hand
half of the screen. Pressing PLOT on the
calculator, or the key labeled will
change the emphasis from the equation back
to the graph.

SYMB mode

In mode the student can change the coefficients directly and see the
changes reflected in the graph.
For example, on the screen shown below, the
'v' coefficient is highlighted and can be
changed using the ↑ and ↓ keys. The size of
the changes to 'h' and 'v' is controlled by the
key, and the same range of values is
available for the values of 'a' as in
mode. You can move from one coefficient to the next by using the
→ and ← keys.
As with the mode, the equation in
2
+bx+c form, its roots and its discriminant
y=ax
are shown on the right half of the screen.
The sequence of three screen shots right show
how the axes automatically re-position to allow
a larger range of values to be explored. There
is a limit to how far the graph can move.
165