# Math Help - Vectors in space

1. ## Vectors in space

I understand the first 2 steps, but not the last.

2. note that $\overrightarrow{OA} + \overrightarrow{OB} = \overrightarrow{OP'}$

3. Originally Posted by skeeter
note that $\overrightarrow{OA} + \overrightarrow{OB} = \overrightarrow{OP'}$
Why do you have to do that kind of a transformation? Why can't I leave it at the second step?

4. I don't think it was a step ... all three vector equations yield the same result.

I guess it's the "Kumon" way of showing you that there's more than one road to get to Dallas.

note that the last expression should be ...

$\overrightarrow{OA} + \overrightarrow{OB} + \overrightarrow{P'P}$

5. Originally Posted by skeeter
note that the last expression should be ...

$\overrightarrow{OA} + \overrightarrow{OB} + \overrightarrow{P'P}$
Well, the solution book says $\overrightarrow {OC}$.

Anyway, $\overrightarrow {OC}=\overrightarrow {P'P}$