The line and the plane meet at:
(3)
Ans. infinitely many points
Explanation:
Direction ratios of given line are 1, -2, 3 and the d.r. of normal to the given plane are 1, 2, 1.
Since 1 × 1 + (-2) × 2 + 3 × 1 = 0, therefore, the line is parallel to the plane.
Also, the base point of the line (1, 2, 1) lies in the given plane.
(1 + 2 × 2 + 1 = 6 is true)
Hence, the given line lies in the given plane.