In ordinary least squared there is this equation (Kevin Murphy book page 221, latest edition)
$$NLL(w)=\frac{1}{2}({y-Xw})^T(y-Xw)=\frac{1}{2}w^T(X^TX)w-w^T(X^T)y$$
I am not sure how the RHS equals the LHS. Maybe my linear algebra is weak but I can't figure out how this happens. Can somebody point out how this happens. This is related to deriving the Ordinary Least squares equation where $\hat{w}_{OLS}=(X^TX)^{-1}X^Ty$
