If the projections of a line segment on the $x, y$ and $z-$ axes in $3-$ dimensional space are $2, 3$ and $6$ respectively,then the length of the line segment is

Find the direction cosines of the line passing through the two points $(-2, 4, -5)$ and $(1, 2, 3)$.

The perpendicular distance of the point $P(6, 7, 8)$ from the $XY$-plane is:

If the direction ratios of a line are $1, 1, 2$,find the direction cosines of the line.

If the angles made by a straight line with the coordinate axes are $\alpha, \frac{\pi}{2}-\alpha, \beta$, then $\beta$ is equal to

Let $ABC$ be a triangle with vertices at points $A(2, 3, 5)$,$B(-1, 3, 2)$ and $C(\lambda, 5, \mu)$ in three-dimensional space. If the median through $A$ is equally inclined with the axes,then $(\lambda, \mu)$ is equal to