Find the distance between (1,0,0,-2) in Euclidean space and a surface L:
Thanks to anyone able to solve it.
Your "surface" is a (two-dimensional) vectorial plane. Find an orthonormal basis of (i.e. find two non-colinear vectors in and orthonormalize them), then the projection of on is (dot products) and thus by "Pythagoras theorem" . I find but I may very well be wrong.