8. The parabola \(P\) has equation \(y ^ { 2 } = 4 a x\), where \(a\) is a positive constant. The point \(S\) is the focus of \(P\). The point \(B\), which does not lie on the parabola, has coordinates ( \(q , r\) ) where \(q\) and \(r\) are positive constants and \(q > a\). The line \(l\) passes through \(B\) and \(S\).

1. Show that an equation of the line \(l\) is $$( q - a ) y = r ( x - a )$$ The line \(l\) intersects the directrix of \(P\) at the point \(C\). Given that the area of triangle \(O C S\) is three times the area of triangle \(O B S\), where \(O\) is the origin,
2. show that the area of triangle \(O B C\) is \(\frac { 6 } { 5 } \mathrm { qr }\)