The angle between two lines having direction ratios 1, 1, 2 and 4 is

The vector equation of the x-axis is given by

The Cartesian equations of a lines are What is its vector equation?

The straight line is

If a line makes angles α, β and γ with the x-axis, y-axis and z-axis respectively then (sin² α + sin² β + sin² γ) = ?