# Thread: straight

1. ## straight

At what point the straight that passes by A(2,3,4) and B(1,0,-2) intercepts the xy plane?

Answer:
$(\frac{4}{3},1,0)$

2. The parametric line equations are:

$x=1+t, \;\ y=3t, \;\ z=-2+6t$

In order to intersect the xy plane, then z must = 0.

So, from z:

$-2+6t=0, \;\ t=1/3$

Insert this into x and y and we get:

$x=4/3, \;\ y=1, \;\ z=0$