Doing Vector math in Geogebra
1.
Enter a vector: Initial point (-2, 6) and terminal point (0, 5). As
Vector[(-2,6),(0,5)]
2.
Enter a vector in component form: 𝑣⃗ = ⟨−7, 8⟩ as:
Vector[(-7, 8)]
3.
Find the magnitude of a vector 𝑣⃗ : (provided you have already entered a vector called v)
Abs(v)
4.
Find the direction angle of a vector 𝑣⃗ : (you must enter component form)
Angle[(3,4)]
*if you enter this in the graph mode, it will display the angle on the graph, and tell you the direction angle in the margin. If you do this in CAS mode, it won’t display the angle, just tell you what it is.
5.
Vector Addition with Geogebra: a.
graph two vectors b.
use the names of the two vectors (i.e.: u+v)
Let’s try some of this out:
Graph the following vectors in Geogebra:
1.
Initial point (-4,3) and terminal point (6,1)
2.
𝑣⃗ = ⟨5, −2⟩

3.
𝑢 (don’t stress over the name of the vector. Just let Geogebra name it whatever it wants.)
4.
Find the magnitude of the 3 vectors.
5.
Find the direction angle of the 3 vectors.
6.
Find the resultant of 3𝑢 (or use the name that geogebra gave them).
7.
Find the direction angle of the resultant from problem 6.
Now let’s use geogebra to solve something more challenging.
8.
An airplane is travelling at a speed of 480 mph. with a bearing of 91⁰ at a fixed altitude, with a negligible wind velocity. As the plane reaches a certain point, it encounters a wind blowing with a velocity of 52 mph with a bearing of S101⁰E. What is the resultant speed and direction of the plane?
Hint: 1. Turn bearings of the plane into a math angle, and the same with the wind direction.
2. use the magnitude and direction angle to find the component form of the plane’s vector and the same for the wind’s vector.
3. Use geogebra to find the resultant vector, then the magnitude, then the direction angle.