Find the orthogonal projection of (1 1 1 1) onto <(1 3 1 1), (2 -1 1 0)>.
I have no problem finding the orthogonal projection of a vector onto another vector, which is (<y, x> x)/<x, x>. However, I don't know how to find the orthogonal projection of a vector onto a scalar. Is there a way to do this?