The direction cosines of the line $\frac{x-1}{0}=\frac{y+1}{5}=\frac{z-3}{0}$ are . . . . . . .

If $OA$ is equally inclined to $OX, OY$ and $OZ$ and if $A$ is $\sqrt{3}$ units from the origin, then $A$ is:

The acute angle between the two lines whose direction ratios $(l, m, n)$ satisfy the equations $l+m-n=0$ and $l^2+m^2-n^2=0$ is

If the projections of a line on the coordinate axes are $4, 6, 12$,what are the direction cosines of the line?

If the direction cosines of two lines are such that $l+m+n=0$ and $l^2+m^2-n^2=0$, then the angle between them is:

If three mutually perpendicular lines have direction cosines $(l_1, m_1, n_1), (l_2, m_2, n_2)$ and $(l_3, m_3, n_3)$,then the line having direction cosines $(l_1 + l_2 + l_3), (m_1 + m_2 + m_3)$ and $(n_1 + n_2 + n_3)$ makes an angle of $...^o$ with each of the original lines.