C
cockanh
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
sai o dau ?
Ta co: vecto a nhan vecto b =0
vecto c nhan vecto b =0
suy ra: vecto a nhan vecto c nhan b binh phuong =0
ma b khac 0 nen vecto a nhan vecto c =0
hay:vecto a vuong goc voi vecto c .........? (vo li qua!)![Frown :( :(](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Frown :( :(](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Frown :( :(](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Frown :( :(](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Ta co: vecto a nhan vecto b =0
vecto c nhan vecto b =0
suy ra: vecto a nhan vecto c nhan b binh phuong =0
ma b khac 0 nen vecto a nhan vecto c =0
hay:vecto a vuong goc voi vecto c .........? (vo li qua!)