Lesson 2.3 · 8 of 25 lessons

Linear combinations

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

    A linear combination multiplies each vector by a coefficient and then adds them

  2. 02

    First add one copy each of u and v

  3. 03

    Now change only the coefficient of u to 2

  4. 04

    The sum out moves with it
    Changing coefficients this way creates a linear combination

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 4/5
coordinates on

1, 2  #u@
2, -1  #v@
// A **linear combination** multiplies each vector by a coefficient and then adds them
focus u v
checkpoint Linear combinations · 1

focus -
// First add one copy each of {{u}} and {{v}}
sum(u, v)  #out@
checkpoint Linear combinations · 2

// Now change only the coefficient of {{u}} to 2
u * 2
// The sum {{out}} moves with it\nChanging coefficients this way creates a **linear combination**
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