AeroLab Reading room

MATH / IGCSE

Transformations and vectors

Translations, reflections, rotations and enlargements map shapes while changing specified features. A vector describes displacement with magnitude and direction.

Learning objectives

The big idea

Translations, reflections, rotations and enlargements map shapes while changing specified features. A vector describes displacement with magnitude and direction.

Add vectors component by component or head to tail. A position vector depends on the chosen origin; the displacement from A to B is OB−OA.

Equations and relationships

AB→=OB→−OA→\overrightarrow{AB}=\overrightarrow{OB}-\overrightarrow{OA}

Subtract starting position from finishing position.

Worked example

A = (1,2), B = (4,6). Find vector AB.

Follow the solution

Subtract components: (4−1,6−2) = (3,4).

Investigate and explain

Predict the worked result before calculating. Change one input, record the new result, and explain which assumptions still hold.

Related interactive model. Compare its assumptions with the explanation; it is not a complete syllabus lesson.

Open the interactive investigation

Check your understanding

1. Which transformation preserves size and orientation?

  1. Translation
  2. Enlargement by factor 2
  3. Reflection
Check the answer and reasoning

Translation

Translation moves every point by the same vector.

2. A = (1,2), B = (4,6). Find vector AB.

  1. (5,8)
  2. (3,4)
  3. (−3,−4)
Check the answer and reasoning

(3,4)

Subtract components: (4−1,6−2) = (3,4).

3. What is the length of vector (3,4)?

  1. 7
  2. 25
  3. 5
Check the answer and reasoning

5

Pythagoras gives √(3²+4²) = 5; 25 is its squared length.