Equation of a line through (5,3,6)and parallel to z−axis is
x−50=y−31=z−60
x−50=y−30=z−61
x−51=y−32=z−65
x−51=y−30=z−60
The direction cosines of z- axis is ⟨0,0,1⟩
The equation of the line passing through the point 5,3,6 and having direction cosines ⟨0,0,1⟩ is x−50=y−30=z−61