Thread: Equation of a plane

I need to find the plane determined by the two intersecting lines. I've done okay so far with similar problems, but never using two lines like this. Any pointing in the right direction would be greatly appreciated!

L1: x= -1+t y= 2+t z= 1-t -inf< t <inf
L2: x= 1-4s y= 1+2s z=2-2s -inf< s <inf

What do you know about the Cross Product?

If the cross product = 0, the vectors are collinear...

First: Do the lines intersect? If so then find the point.
Second: Find the cross product of the two direction vectors. That is the plane’s normal.
Third: Write the equation of the plane.

Originally Posted by mistykz

If the cross product = 0, the vectors are collinear...

No, no. That's the dot product, or the inner product. This is a scalar concept. You need the VECTOR concept of a Cross Product.