The dot product is used to determine the extent to which two vectors point in the same direction.
Or, if solving for 𝛳, it will tell you the angle between two vectors.
Physics: Calculating Work Done on an Object
Game Development: Reflection of Light
Machine Learning: Find Similarity of Two Data Points
Recommendation systems
Facial comparison software
Change v0 (velocity) and theta (kick angle) and watch how the dot products (green arrows) change.
Cross product formula between any two vectors gives the area between those vectors and the magnitude of the resultant vector perpendicular to them.
Physics: Angular momentum
Astronomy: position and momentum of planet to determine its orbit
Wind & Ocean Currents
Sports: Find Football/Baseball Trajectory
Or any object spinning!
Change the direction, velocity, and spin on the ball and watch its trajectory change! Pay attention to which direction the arrows are going on different frames!