Problem:
Fix some vector ##\vec{a} \in R^n \setminus \vec{0}## and define ##f( \vec{x} ) = \vec{a} \cdot \vec{x}##. Give an expression for the maximum of ##f(\vec{x})## subject to ##||\vec{x}||_2 = 1##.
My work:
Seems like a lagrange multiplier problem.
I have ##\mathcal{L}(\vec{x},\lambda)...