finding rotation matrix in 3d
suppose I have a normalized vector perpendicular to a plane like
x=(2i+3j+k)√14 , how can I find a rotation matrix A, such that it rotates x into the xy plane like so:
Ax=y=(i,j)√2
This is a linear algebra question, not a question about Sage. Try asking on http://math.stackexchange.com/
Look at http://www.hr.shuttle.de:9000/home/pub/105/ There is an example.
why did you rotate the vector around z axis? can't we rotate it around x and y axes instead?
Your original question doesn't have a unique answer. There are infinitely many rotations that take your vector `x` to a vector in the XY-plane.