Played 1 times
A review of what you need to know about vectors for IGCSE
A vector has both magnitude and direction
Vectors can describe translations
Vectors can be added, subtracted and multiplied by a scalar (fancy maths word for a number)
Position vectors always start from the origin
There's lots more to know about vectors but not for IGCSE
How to represent a vector
1. Column vector
2. Line with an arrow
Write vector A as a column vector. Click on the correct answer below.
Vector B can be written as a column vector where the top number is m and the bottom number is n. What is the value of n?
Vector B can be written as a column vector where the top number is m and the bottom number is n. What is the value of m?
Magnitude of a vector
To find the magnitude of a vector we use Pythagoras theorem. Don't forget the notation!
The magnitude of this vector iswhat is the value of k?
A vector goes from the point (-2,7) to the point (4,5) it's magnitude iswhat is the value of m?
Vectors to describe translations.
Triangle C is translated by vector a to give triangle C'. Where will the new triangle be? What are the coordinates of P' (where point P ends up)?
Where was triangle C'?
If you answered that the coordinates of P' were (0,2) then you are correct! This translation moves the triangle 4 to the right and down 1.
What is the distance between triangle C and triangle C'?
Did you realise that the distance between the 2 triangles is the magnitude of vector a (remember we write that|a|)?
Multiplying a vector by a scalar.
(A scalar is just a fancy word for number)
Multiplying a vector by a negative number.
Multiplying a vector by a fractional scalar.
How to add column vectors.
Enter the numbers a,b - you need to type in the 2 numbers separated by a comma with no space.
How to add vectors graphically.
Draw the first vector and where it finishes start drawing the second vector.
How to subtract column vectors.
Subtracting vectors graphically
As for addition draw the first vector and then at the end of it draw the second vector but going in the opposite direction.
The position vector is the vector from the origin to a point.
Now lets try a few IGCSE questions
Don't include any spaces in your answer.
Try this question on paper. Then check your answers on the next slide.
Here are the answers. On the next slide you can see a video explanation of how I got them.
Explanation of the last question.