Edexcel IGCSE Maths 复习笔记 5.1.4 Vectors - Modulus
What is a vector?
- Vectors have various uses in mathematics
- In mechanics vectors represent velocity, acceleration and forces
- At IGCSE vectors are used in geometry – eg. translation
- Ensure you are familiar with the Revision Notes Vectors – Basics
- Vectors have magnitude and direction
- These notes look at finding the magnitude, or modulus, of a vector
- Vectors are given in column vector form
What is the magnitude or modulus of a vector?
- This depends on the use of the vector
- For velocity, magnitude would be speed
- For a force, magnitude would be the strength of the force (in Newtons)
- The words magnitude and modulus mean the same thing with vectors
- In geometry magnitude and modulus mean the distance of the vector
- This is always a positive value
- The direction of the vector is irrelevant
- Magnitude or modulus is indicated by vertical lines
- |a| would mean the magnitude of vector a
How do I find the magnitude or modulus of a vector
- Pythagoras’ Theorem!
Exam Tip
Sketch a vector to help, it does not have to be to scale – you can then use this to form a right-angled triangle.
Worked Example
转载自savemyexam
