1.

Show that the points A, B and C having position vectors (i + 2j + 7k),(2i + 6j + 3k) and (3i + 10j - 3k) respectively, are collinear.

Answer»

A =  \(\vec{i}+2\vec{j}+7\vec{k}\)

B =  \(2\vec{i}+6\vec{j}+2\vec{k}\)

 C =  \(3\vec{i}+10\vec{j}-3\vec{k}\)

\(\vec{AB}\)

\((2\vec{i}+6\vec{j}+2\vec{k})\) - \((\vec{i}+2\vec{j}+7\vec{k})\)

=    \(\vec{i}+4\vec{j}-5\vec{k}\)

 \(\vec{BC}\) 

  \((3\vec{i}+10\vec{j}-3\vec{k})\) - \((2\vec{i}+6\vec{j}+2\vec{k})\)

=    \(\vec{i}+4\vec{j}-5\vec{k}\)

 \(\vec{AB}\) =  \(\vec{BC}\) 

So, the points A, B and C are collinear.



Discussion

No Comment Found

Related InterviewSolutions