The Parabola P : y2 = x.
(1) The line y = k cuts P exactly once.
(1) The line y = k cuts P where y = k and y2 = x, so x = k2.
Thus the line cuts the parabola only at (k2,k).
(2) Where the line meets the parabola, x = ny+c and y2 = x,
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