InterviewSolution
Saved Bookmarks
| 1. |
The three vectors a, b and c with magnitude 3, 4 and 5 respectively and a+b+c=0, then the value of a.b+b.c+c.a is |
|
Answer» `-23` On squaring both SIDES, we get `|a+b+c|^(2)=0` `RARR a^(2)+b^(2)+c^(2)+2(a*b+b*c+c*a)=0` `rArr 2(a*b+b*c+c*a)=-(9+16+25)` `THEREFORE a*b+b*c+c*a=-25` |
|