# Math Help - A question about vector

1. ## A question about vector

If x is a vector,and center it on the origin,but what dose the formula (x.1=0) mean?I am puzzled about why there is a point symbol behind vector x,and what does 1 mean?
I really appreciate your help! The image below is the original text

2. ## Re: A question about vector

Hello,

Common notation for the scalar product.

3. ## Re: A question about vector

hi,can you speak in detail? My english is very poor,and can you give me a example? thank you very much

4. ## Re: A question about vector

You mean the point symbol means scalar product?but 1 means a vector that each element equals to 1?

5. ## Re: A question about vector

Originally Posted by Moo
Hello,

Common notation for the scalar product.
You mean the point symbol means scalar product?but 1 means a vector that each element equals to 1?

6. ## Re: A question about vector

Originally Posted by ChinaPanda
You mean the point symbol means scalar product?but 1 means a vector that each element equals to 1?
Yes, 1 stands for $\begin{pmatrix} 1\\1\\ \vdots \\ 1\end{pmatrix}$

This scalar product will actually give the sum of x's components.

duibuqi, wo bu hui shuo zhongwen shuxue

7. ## Re: A question about vector

Originally Posted by Moo
Yes, 1 stands for $\begin{pmatrix} 1\\1\\ \vdots \\ 1\end{pmatrix}$

This scalar product will actually give the sum of x's components.

duibuqi, wo bu hui shuo zhongwen shuxue

wow ,you're great! scalar product in chinese is dian cheng,dian (点)means a point,cheng(乘)means product