Linear Algebra, Matrix, Mathematics, Math, Machine Learning.
directions: up-down and left-right. Or it might be floating in the air, adding a forward-backward direction, making it 3D space. The lenght in R2 and R3 The figure above shows the two cases to find the length of a vector: In 2D Space (like a piece of paper): use Pythagoras’ theorem = √(x1² + x2²).