posted by Anon .
a) Find parametric equations for the line through (4, 1, 4) that is perpendicular to the plane x − y + 2z = 7. (Use the parameter t.)
b) In what points does this line intersect the coordinate planes?
the normal to the plane has direction cosines proportional to <1,-1,2>, so
x = 4+t
y = 1-t
z = 4+2t
z=0, so t = -2
and so on