TAG | pythagoras theorem
In Secondary 4, students are going to learn this chapter ‘Vectors’. Some love it, most hate it.
In today post, I’m going to share some basic concepts on Vectors.
What is a vector?
A vector is a quantity that has direction and magnitude. Common examples of vector include velocity, acceleration, displacement and force.
The opposite of vector is scalar, a quantity that has only magnitude. Examples include time, speed, distance and mass.
As you see, vector is closely associated with physics!
How do we represent a vector?
vector
Since vector involves magnitude and direction, there will always be an arrow indicting the direction. We call this vector 
Vectors can be expressed in a column format called column vector. For this example, 
which means, starting from point A, 3 units to right and 1 unit up. It is similar to our coordinate system 3 units along x axis and 1 unit along y axis. In general, moving right and up have positive sign while moving left and down have negative sign.
In general: 
How to find magnitude of a vector?
Using the same example,to find magnitude of 
, we use Pythagoras’s Theorem. (Refer to diagram above)
Magnitude of can be written as 
.
I hope you have understood the basic concepts of vectors. In future post, I’m going to write more about the application of vectors.
