# Thread: Tangent plane parallel to another plane

1. ## Tangent plane parallel to another plane

The example i missed from my lectures is:
Find all points on the ellipsoid 2x^2+3y^2+4z^2=9 at which the tangent plane is parallel to the plane x -2y +3x=5.

How would you do this? Can someone show me please?
Thanks

2. Originally Posted by Sam1111
The example i missed from my lectures is:
Find all points on the ellipsoid $\displaystyle 2x^2+3y^2+4z^2=9$ at which the tangent plane is parallel to the plane $\displaystyle x -2y +3x=5$.

How would you do this? Can someone show me please?
Thanks
A very similar question was asked and solved here. Use the same method; just substitute in your numbers.

3. Thanks

4. Would you be able to finish this problem for me. I can understand it but (x,y,z) must be on the surface so they have to satisfy the original surface equation right?

So I put the scaled values of (x,y,z) into 2x^2+3y^2+4z^2=9

When I went through the problem I got these large and awkward numbers so I'm thinking I messed up somewhere.

Thanks