Given the points $\mathrm { P } ( - 3,1,2 )$ and $\mathrm { Q } ( - 1,0,1 )$ and the plane $\pi$ with equation $x + 2 y - 3 z = 4$, it is requested:\ a) (1 point) Find the projection of $Q$ onto $\pi$.\ b) (0.5 points) Write the equation of the plane parallel to $\pi$ that passes through point $P$.\ c) (1 point) Write the equation of the plane perpendicular to $\pi$ that contains points $P$ and $Q$.