2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/91751In this paper I show that any $m$th-degree polynomial function of the elements of the density matrix $ρ$ can be determined by finding the expectation value of an observable on $m$ copies of $ρ$, without performing state tomography. Since a circuit exists which can approximate the measurement of any observable, in principle one can find a circuit which will estimate any such polynomial function by averaging over many runs. I construct some simple examples and compare these results to existing procedures.Minor revisions in response to referee commentsQuantum Physicstext