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**MaxT****Member**- Registered: 2023-01-09
- Posts: 3

Hello,

Can someone help me with basic vector multiplication please.

I understand (I think!) dot product (scalar result) and cross product (vector result), but I was watching a video where someone did this

writing this in the format of x axis, y axis...

vector a: 3, 1.5

vector b: 3, 5

and multiplied them as:

3 x 3 = 9

1.5 x 5 = 7.5

claiming the result of multiplying the vectors was a vector: 9, 7.5

Is that right?

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**MaxT****Member**- Registered: 2023-01-09
- Posts: 3

Yes - that's what I thought was right - a scalar of 16.5

So, is the operation I wrote out - which I saw someone else do - not a valid operation at all?

I didn't think it was but it left me confused.

*Last edited by MaxT (2023-01-09 00:43:44)*

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**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 41,293

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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MaxT wrote:

Yes - that's what I thought was right - a scalar of 16.5

So, is the operation I wrote out - which I saw someone else do - not a valid operation at all?

I didn't think it was but it left me confused.

It's a perfectly valid operation, just that the answer should have been a scalar (rather than a vector), i.e.

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**MaxT****Member**- Registered: 2023-01-09
- Posts: 3

Yes - thank, I understand that.

The confusion was that the person in the video I watched GRAPHED that 9 + 7.5 result as a VECTOR!!

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**imcute****Member**- Registered: 2022-09-28
- Posts: 176

You cannot multiply two vectors like when you add them.

(it is correct in a CS perspective but not in a math perspective)

Dot product is what you was wanting to do.

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