Casio fx-7400G, User Manual

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158
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 (Ma 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
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
Memory
Contents