3 The plane \(\Pi\) passes through the points \(( 1,2,1 ) , ( 2,3,6 )\) and \(( 4 , - 1,2 )\).
- Find a cartesian equation of the plane \(\Pi\).
The line \(l\) has equation \(\mathbf { r } = \left( \begin{array} { r } - 1
- 2
6 \end{array} \right) + \lambda \left( \begin{array} { r } 4
3
- 2 \end{array} \right)\). - Find the coordinates of the point of intersection of \(\Pi\) and \(l\).
- Find the acute angle between \(\Pi\) and \(l\).