Mammoth Memory

Subtracting column vectors

Subtract just like any normal calculation but keep the top row separate from the bottom row.

 

Example 1

Take vector `a` and subtract vector `b`

vector `a=((2),(3))`  vector `b=((3),(2))`

vector `a-b=((2-3),(3-2))=((-1),(1))`

Shown graphically:

You can always check that you have the right answer when subtracting column vectors by showing it graphicaly as well

vector `c=((-1),(1))`

 

Example 2

If vector `e=((3),(4))` and vector `f=((-1),(4))`

What is `e-f`  ?

`((3),(4))-((-1),(4))=((3-(-1)),(4-4))=((4),(0))`

Remember two minuses together is a positive.

Shown graphically:

 After reversing a vector to make a triangle all you need to do is subtract one vector with the other to make the resultant vector

`e-f=((4),(0))`

 

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