Mammoth Memory

Subtracting vectors

Subtracting - Reverse

Reverse the direction of the vector you want to subtract


Example 1

Subtract vector `a`  from vector `b`

Take 2 vectors one with a height of 3 and the other a height of 2 

Draw the vectors together as you were adding them

Place the first vector `a`  and add on the reverse of vector `b`

The result is a new vector `c`

Draw the first vector down completely so you can start to see a triangle



It doesn't matter in which order you subtract vectors or add vectors. Therefore:


But try `-b+a` and see for yourself.

But try `-b+a` and see for yourself.

`a-b=c`  and `-b+a=c`

Another way of showing `a-b=-b+a`  is as follows:


Example 2

Remember you can subtract and add vectors in any order as long as they join 


Connect a vector to the opposing corners then minus two of the sides



Example 3

You can connect any vectors up as long as they meet, but the parallel vector to the resultant vector needs to be negative 

Vector `r=a-b+c+d`



When subtracting vectors remember to turn the parallel vector to the resulting vector is negative 

Vector `r=c+a-b+d`


You can add vectors and reversed vectors in any order.

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