What is the vector?

What to learn

- What is the vector?
- How to sum(multiply) vectors ## Description
- Vector is the main components of Linear Algebra
- What exactly vector is?
    - three distinct ideas
        - Physics
            - Vectors are arrows pointing in space
                - Two Elements
                    - length
                    - direction
                - regardless starting point
        - Computer Science
            - order list of number
        - Mathematicsian
        - In this video
            - think vector as arrow from origin
            - think arrows and list alternately(It dosen't matter how we think between them cause it can be alternative each other)
    - **Summation**
        - Think vector A and vector B.
        - we can think A+B as new vector
            - move B's starting point to A's end point. and draw new vector that start from A's starting point to B's end point
    - **Multiplication**
        - Think vector A and scala B
            - if B is positive, then squeeze or expand A by B
            - if B is negative then A is flipped based on starting point and squeezed or expanded ## Next Step - Linear combinations, span and bases

References

  1. https://www.youtube.com/watch?v=fNk_zzaMoSs&list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab