text: find the equ. of the plane containg the two(parralle) lines;? r(1)=(0,1,-2) + t(1,-2,4) and r(2)=(-5,3,1) + t(1,-2,4) anyhelp will be great i have a final 2morrow and i need to find out thanks. there are various ways you can proceed.  r(1)=(0,1,-2) + t(1,-2,4) and r(2)=(-5,3,1) + t(1,-2,4)  one way is to find a normal to the plane first and then a point on the plane and write the equation in point normal form. the thing to understand here is that by giving various values to t you obatin various point all of them on the plane.  so let us find two points on r(1) and one point on r(2) two points on r(1) put t=0,1 you have  (0,1,-2),(1,-1,2)  and r(2) put t=0 you have  (-5,3,1) so you have three points on a plane which are not all collinear because we chose one of them from second line. so you can write the standard equation of plane passing through these three points. if you need more help then note that if you name these three points as r1,r2,r3 then  (r1-r3)cross(r2-r3) = vector normal to the plane (5,-2,-3)cross(6,-4,1)=vector normal to the plane form the determinant find the normal. then you have the normal take any of the points r1,r2,r3 and form the equation in point normal form.