E-CodeVectors: dot, cross, angle, projection — a TI-84 Plus CE program
VECTOR3 is a TI-BASIC program for the TI-84 Plus CE. Type two 2-D or 3-D vectors: lengths, dot product, the angle between them in degrees, the cross product with the parallelogram and triangle areas, and the projection of U onto V.
What it asks for and what it shows
It asks for 2 values at its prompts. In the example below it shows LEN U, LEN V, U DOT V, CX, CY, CZ, AREA, TRIAREA, DEG ANG, PX, PY, PZ, SCALAR.
Example run
One of its oracle test cases: “3-D textbook”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | {1,2,3} |
| Input 2 | {4,⁻5,6} |
| The screen shows | |
LEN U= | 3.741657387 |
LEN V= | 8.774964387 |
U DOT V= | 12 |
CX= | 27 |
CY= | 6 |
CZ= | -13 |
AREA= | 30.56141358 |
TRIAREA= | 15.28070679 |
DEG ANG= | 68.56244697 |
PX= | 0.6233766234 |
PY= | -0.7792207792 |
PZ= | 0.9350649351 |
SCALAR= | 1.367526918 |
How it's checked
6 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 75 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-84 Plus CE calculator and pick “Vectors: dot, cross, angle, projection” (VECTOR3).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
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All TI-84 Plus CE math programs · All TI-84 Plus CE programs