A source with a strength of \(q=3 \pi \mathrm{m}^{2} / \mathrm{s}\) and a sink with a strength of \(q=\pi \mathrm{m}^{2} / \mathrm{s}\) are located on the \(x\) axis at \(x=-1 \mathrm{~m}\) and \(x=1 \mathrm{~m}\), respectively. Determine the stream function and velocity potential for the combined flow and sketch the streamlines.