De rien, (Are you french either by the way? )
Yes you have to reduce this term. If you suppose that P is \mathscr{C}^2 then you can choose whether x or z thanks to Cauchy-Schwarz, otherwise you should do the integration by part over x.
De rien, (Are you french either by the way? )
Yes you have to reduce this term. If you suppose that P is \mathscr{C}^2 then you can choose whether x or z thanks to Cauchy-Schwarz, otherwise you should do the integration by part over x.