InterviewSolution
Saved Bookmarks
| 1. |
If a,b,c and A,B,C inR-{0} such that aA+bB+cD+ sqrt((a^(2)+b^(2)+c^(2))(A^(2)+B^(2)+C^(2)))=0, then value of (aB)/(bA) +(bC)/(cB) + (cA)/(aC) is |
|
Answer» 3 `therefore costheta=(veca.(vecb+vecc))/(|veca||vecb+vecc|)` `=(2cosalpha)/sqrt(2+2cosalpha) = (cosalpha)/(cosalpha/2)` `therefore theta=cos^(-1)(cosalpha)/(cosalpha/2)` `therefore vecr_(1)vecr_(2)-|vecr_(1)||vecr_(2)|` `rArr vecr_(1)` and `vecr_(2)` are anti-parallel `rArr a/A=b/B=c/C=k` where k is any constant `rArr (aB)/(bA) +(bC)/(cB) + (cA)/(aC)=3` |
|