Graphing Hyperbolas - Sharp EL9600C - Graphing Calculator Handbook

Graphing Hyperbolas

The standard equation for a hyperbola can take one of two forms:
2
2 ( y - k )
( x - h )
- = 1 with vertices at ( h
2 2
a b
2
( y - h)
( x - k ) 2
- = 1 with vertices at ( h, k
2
a
2
b
There is a problem entering this equation in the calculator graphing list for two reasons:
a) it is not a function, and only functions can be entered in the Y= list locations.
b) the functions entered in the Y= list locations must be in terms of x, not y.
To draw a graph of a hyperbola, consider the "top" and "bottom" halves of the hyperbola
as two different parts of the graph because each individual is a function. Solve the equation
of the hyperbola for y and enter the two parts in two locations of the Y= list.
Example
Graph a hyperbola in rectangular mode. Solve the equation for y to put it in the
standard form.
Graph the hyperbola x
Before There may be differences in the results of calculations and graph plotting depending on the setting.
Start
Return all settings to the default value or to delete all data.
Set the zoom to the decimal window:
Step & Key Operation
(When using EL-9600)
*Use either pen touch or cursor to operate.
1 Solve the equation for y completing
the square.
Enter
Y1 = x 2
Y2 = Y1 -3
Y3 = -Y1 -3
Y=
2nd F
+
n 1
X/ /T/
VARS A ENTER
*
-
( )
A
VARS
*
2
Turn off Y1 so that it will not graph.
10-4
2 2
+ 2x - y - 6y + 3 = 0
A
ZOOM
*
+ 2x + 12
+
n
x 2
2
X/ /T/
2
ENTER
*
1 — 3
ENTER
* *
— 3
1
ENTER
*
ENTER
* *
EL-9600/9400 Graphing Calculator
a, k ) or
b ).
( )
7
ENTER ALPHA
* *
Display
(When using EL-9600)
2
x
2
x
2
x
(y + 3)
y + 3 =
y =
Notes
2
+ 2x - y -6y = -3
2
+ 2x - (y + 6y + 9) = -3 -9
2
+ 2x - (y +3) = -12
2 = x 2 + 2x + 12
+
2
x + 2x + 12
+
2 + 2x + 12 - 3
x