TI-60 Geometry: Intersection and Angle Between Two Lines
We have two lines in the standard form:
y = R1 * x + R2
y = R3 * x + R4
where R1, R3 are the slopes and R2, R4 are the y-intercepts, which are stored prior to executing the programs.
TI-60: Intersection Point
x = (R4 – R3) / (R1 – R3), y = R1 * x + R2
Step Key Code |
Key |
Step Key Code |
Key |
00 53 |
( |
14 54 |
) |
01 71 |
RCL |
15 95 |
= |
02 04 |
4 |
16 13 |
R/S |
03 75 |
- |
17 65 |
× |
04 71 |
RCL |
18 71 |
RCL |
05 02 |
2 |
19 01 |
1 |
06 54 |
) |
20 85 |
+ |
07 55 |
÷ |
21 71 |
RCL |
08 53 |
( |
22 02 |
2 |
09 71 |
RCL |
23 95 |
= |
10 01 |
1 |
24 13 |
R/S |
11 75 |
- |
25 22 |
RST |
12 71 |
RCL |
|
|
13 03 |
3 |
|
|
TI-60: Angle Between Two Lines
Θ = arctan(abs((R1 – R3) / (1 + R1 * R3)))
Step Key Code |
Key |
Step Key Code |
Key |
00 53 |
( |
13 65 |
× |
01 71 |
RCL |
14 71 |
RCL |
02 01 |
1 |
15 03 |
3 |
03 75 |
- |
16 54 |
) |
04 71 |
RCL |
17 95 |
= |
05 03 |
3 |
18 96 |
x² |
06 54 |
) |
19 86 |
√x |
07 55 |
÷ |
20 12 |
R/S |
08 53 |
( |
21 34 |
RST |
09 01 |
1 |
|
|
10 85 |
+ |
|
|
11 71 |
RCL |
|
|
12 01 |
1 |
|
|
Examples
|
Intersection Point: (x, y) |
Angle: Θ (degrees) |
y = -2 * x + 3 y = 3 * x + 4 |
(-0.2, 3.4) |
45° |
y = x + 8 y = 3 * x – 6 |
(7, 15) |
26.56505118° |
y = 4 * x – 6 y = 2 * x + 1 |
(3.5, 8) |
12.52880771° |
May I close with this: Happy Birthday, Susan Sarandon!
Eddie
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