I'm stuck on this review problem for our final:
The projection of X onto (a,b) = (a,b)
X is orthogonal to (-a,b)
Describe the norm of X in terms of a and b.
The Attempt at a Solution
I drew everything out on a Cartesian system, with the vector X being perpendicular to (-a,b) and then draw the projection of (a,b). I saw that since X is orthogonal to (a,b) it would have a slope of a/b and then attempted to use (y-y1)=m(x-x1) but that failed.
I really have no idea how to solve this and would greatly appreciate any help. Thanks