Sharp EL-9900 Handbook Vol. 1 Operation Manual page 12

Step & Key Operation
2
1
-
Change the equation in Y2 to y = x
Y= 2nd F
2
ENTER ENTER
2
2
- View both graphs.
GRAPH
3
1
- Change the equation in Y2 to y = 2x
Y=
2nd F
0
ENTER
3
2
-
View both graphs.
GRAPH
4
1
-
Change the equation in Y2 to
2
y = - 2x .
Y=
2nd F
ENTER
4
2
-
View both graphs.
GRAPH
The EL-9900 allows various quadratic equations to be graphed easily. Also the
characteristics of quadratic equations can be visually shown through the
relationship between the changes of coefficient values and their graphs, using
the Substitution feature.
4-1
2
+2.
SUB 0
fact that adding k (>0) within the standard form y = a (x -
h) + k will move the basic graph up k units and placing k
2
(<0) will move the basic graph down k units on the y-axis.
2
.
2
SUB ENTER
-
( )
2
SUB
ing an a (<-1) in the standard form y = a (x - h)
will pinch or close the basic graph and flip it (reflect
it) across the x-axis.
EL-9900 Graphing Calculator
Display
Notice that the addition of 2 moves
the basic y = x
and the addition of - 2 moves the
basic graph down two units on
the y-axis. This demonstrates the
Notice that the multiplication of
2 pinches or closes the basic
y = x 2 graph. This demonstrates
the fact that multiplying an a
(> 1) in the standard form y = a
(x - h) + k will pinch or close
2
the basic graph.
Notice that the multiplication of
-2 pinches or closes the basic
2
y =x graph and flips it (reflects
it) across the x-axis. This dem-
onstrates the fact that multiply-
Notes
graph up two units
2
2
+ k