(a) Find the equation of a line passing through the point $(1, -1, 2)$ and parallel to x-axis. Also, find the shortest distance between this line and the line $\vec{r} = 2\hat{i} + \hat{j} - \hat{k} + \mu$3\hat{i} - 5\hat{j} + 2\hat{k}$$्ले. OR (b) Find the equations of the lines AC and BD, if coordinates of points A, B, C and D respectively, are $(3, -4, 2), (-1, -2, 0), (4, 1, -1)$ and $(4, 0, 5)$. Show that the lines AC and BD are perpendicular to each other.