# Thread: vector question help pls

1. ## vector question help pls

the line L has equation
r=4i +2j -k + t(2i -j -2k). given that l lies in the plane with equation
2x + by+ cz =1 where b and c are constants

find the values of b and c

and also

the point P has psition vector 2j + 4k. show that the perpendicular distance frm P to L is square root of 5

2. Originally Posted by vserian
the line L has equation
r=4i +2j -k + t(2i -j -2k). given that l lies in the plane with equation
2x + by+ cz =1 where b and c are constants find the values of b and c
The point $(4,2,-1)$ must be in the plane $2x+by+cz=1$.
This dot prpduct $\left\langle {2,b,c} \right\rangle \cdot \left\langle {2, - 1, - 2} \right\rangle = 0$ must hold.
That give two equations in two variables.