Lesson 2.4 · 9 of 25 lessons

Independence & dependence

Grow from linear combinations to independence, bases, the fundamental subspaces, and transformations.

Open the interactive animation

01 · Story

What to verify in this scene

Follow the explanations and operations, then identify the mathematical evidence that remains in the final scene.

  1. 01

    Neither a nor b is a scalar multiple of the other, so they provide two directions

  2. 02

    αa + βb = 0 only when α=β=0
    The two vectors are linearly independent

  3. 03

    Now consider a vector that is a multiple of the other

  4. 04

    q is 2p, so it repeats the same direction
    It adds no new direction, making the pair linearly dependent

02 · Notebook

The runnable notebook

This source creates the mathematical objects and controls the order of operations and animation. Read it here, then play the same scene yourself.

2d
zoom 1
coordinates on

2, 1  #a@
-1, 2  #b@
// Neither {{a}} nor {{b}} is a scalar multiple of the other, so they provide two directions
focus a b
checkpoint Independence & dependence · 1

// `α{{a}} + β{{b}} = 0` only when `α=β=0`\nThe two vectors are **linearly independent**
checkpoint Independence & dependence · 2

focus -
clear
1, 1  #p@
// Now consider a vector that is a multiple of the other
2, 2  #q@
// {{q}} is `2{{p}}`, so it repeats the same direction\nIt adds no new direction, making the pair **linearly dependent**
focus p q
Open the interactive animation

03 · Unit 2

Lessons in this unit

Vector spaces & transformations — Grow from linear combinations to independence, bases, the fundamental subspaces, and transformations.

  1. 2.1Vectors & scalars
  2. 2.2Vector addition
  3. 2.3Linear combinations
  4. 2.4Independence & dependence
  5. 2.5Bases & coordinates
  6. 2.6Column space & null space
  7. 2.7Scaling & rotation