# Gradient Vector (Context: Ridge Regression - Analytical Question)

I am solving for an analytical solution to $$arg \min_\beta J(\beta)$$ where $$J(\beta) = (y - A\beta)^T(y - A\beta) + a\|\beta\|^2$$

When deriving in the following, I am curious if there is a rule to determine whether or not the result is a row or column vector.

$$\frac{\partial\beta^T\beta}{\partial\beta} = 2\beta$$

but could also be $$2\beta^T$$ correct?

• Oct 9 at 19:22