Casio fx-9750G PLUS - Manual (Page 446)

418
PROGRAM SHEET
Program for
Circle and Tangents
Description
Formula for circle:
x 2 + y 2 = r 2
Formula for tangent line passing
through point A (
x' , y' ):
y – y' = m ( x – x' )
* m represents the slope of
the tangent line
With this program, slope m and intercept b (= y' – mx' ) are obtained for lines drawn from
point A ( x' , y' ) and are tangent to a circle with a radius of r . The trace function is used to read
out the coordinates at the points of tangency, and factor zoom is used to enlarge the graph.
Example
To determine m and b for the following values:
r = 1
x' = 3
y' = 2
Notes
• The point plotted for A cannot be moved. Even if it is moved on the graph, the calculation is
performed using the original value.
• An error occurs when r = x' .
• Be sure to always perform a trace operation whenever you select trace and the message
TRACE is on the display.
Preparation and operation
• Store the program written on the next page.
• Execute the program as shown below.
No.
4
Memory
Contents
0 X
Y
A
(x',y')
r
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z