Let O\((\alpha, \beta, \gamma)\) be the image of the point P(3, 2, 1) in the plane
2x - y + z + 1 = 0
PO is perpendicular to the plane and S is the mid-point of PO and the foot of the perpendicular.
Dr's of PS are 2, -1, 1.
\(\therefore\) Equation of PS are
\(\therefore\) General point on line is S(2μ + 3, - μ + 2, μ + 1)
If this point lies on plane, then
\(\therefore\) Coordinates of S are (1, 3, 0).
As S is the mid point of PO,
\(\therefore\) The coordinate of
By comparing both sides, we get
Image of point P is (-1, 4, -1).
