2 The point \(A\) has coordinates \(( 1,1 )\) and the point \(B\) has coordinates \(( 5 , k )\).
The line \(A B\) has equation \(3 x + 4 y = 7\).
- Show that \(k = - 2\).
- Hence find the coordinates of the mid-point of \(A B\).
- Find the gradient of \(A B\).
- The line \(A C\) is perpendicular to the line \(A B\).
- Find the gradient of \(A C\).
- Hence find an equation of the line \(A C\).
- Given that the point \(C\) lies on the \(x\)-axis, find its \(x\)-coordinate.