Differentiation of $xx^T$ where $x$ is a vector How is differentiation of $xx^T$ with respect to $x$ as $2x^T$, where $x$ is a vector? $x^T $means transpose of $x$ vector.

Differentiation of $xx^T$ is a 3 dimensional tensor to the best of my knowledge,with each element in the matrix $xx^T$ to be differentiated by each element of the vector $x$,and you can just see the result of a derivative online at site  http://www.matrixcalculus.org/.Any further communication is preferred.
