find the image of point (1,2,3) in the plane 3x+2y-z=8
let Q be the image of the point P(1, 2, 3) in the plane 3x+2y-z = 8.
then PQ is normal to the plane. therefore , direction ratios of PQ are 3, 2,-1.
since PQ passes through P(1,2,3) and has direction ratios 3,2,-1.
therefore the equation of PQ is .
let the coordinates of Q be .
let R be the mid point of PQ. then R, lies on the plane 3x+2y-z = 8.
the coordinates of R are:
since R lies on 3x+2y-z = 8
therefore
hence the coordinates of Q are
i.e.
hope this helps you.
cheers!!