Q. Let be a triangle with vertices at points and in three dimensional space. If the median through A is equally inclined with the axes, then is equal to:

 4123  197 JEE MainJEE Main 2013Three Dimensional Geometry Report Error

Solution:

Since is the median

Now, dR’s of AD is


Also, a, b, c are dR’s
where
and

Now, and

Solution Image