isnt the answer ment to be a vectorOmium said:ok
What i do is initially let "Lamda" = 0 to get your first point on the line
which will be (1,0,2)
Next just choose "Lamda" = 1 to get another point on the line. this other point will now be (0,1,4)
Now the point is (-2,2,7)
So let A = (1,0,2) let B = (-2,2,7) and let C = (0,1,4)
so Vector AB = (-3,2,5)
and Vector AC = (-1,1,2)
So Proj(b)A = (-1,1,2)(-3,2,5)/|(-1,1,2|)
So this = 15/(squareroot of 6)
Now length of AB = Squareroot of 38.
so using pythagoras we get
37.5 + x^2 = 38
x= 1/root(2)