HP 40gs HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010.p - Page 160

SYMB mode, Test mode, mode, since their effects are

Page 160 highlights

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 equation in the form y=ax2+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 The alternative to graphical mode is symbolic mode. In directly and see the changes reflected in the graph. mode the student can change the coefficients For example, on the screen shown below, the 'v' coefficient is high­ lighted 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 y=ax2+bx+c form, its roots and its discriminant are shown on the right half of the screen. The + and - keys are disabled in mode, since their effects are controlled instead by the and keys once the highlight is on the 'a' coefficient. The key controls the sign of 'a'. Test mode The final key is labeled . This key will present the student with a series of graphs for which they must supply the equation. The type of graph is governed by the current setting of . For example, if the current setting of was at Y = X 2 + v then the test graphs would also only use the v parameter instead of a, h and v simultaneously. The setting of can be changed within the screen using the key supplied. 160

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SYMB mode
Test mode
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 equation in
the form
y=ax
2
+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.
The alternative to graphical mode is symbolic 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 high
-
lighted 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
y=ax
2
+bx+c
form, its roots
and its discriminant are shown on the right half of the screen.
The + and - keys are disabled in
mode, since their effects are
controlled instead by the
and
keys once the highlight is on the ‘a’
coefficient. The
key controls the sign of ‘a’.
The final key is labeled
. This key will present the student with a
series of graphs for which they must supply the equation.
The type of graph is governed by the current setting
2
. For example, if the current setting of
=
+
was at
Y
X
v
then the test graphs would also
only use the
v
parameter instead of
a
,
h
and
v
simultaneously.
The setting of
of
can be changed within
the
screen using the key supplied.
160