MPT occurs when the voltage is 1/2 the no load voltage in a linear system. (In PV current sources it’s about 70 to 82%)
In theory (and practise) MPT is when conjugate complex impedances are matched.
\$P_{total}=(\dfrac{V_g^2}{R_g+R_L})=\dfrac{V_g^2}{2R_g}\$ since both R’s are equal.
But the generate absorbs 50% of the MPT and only “generates” 50% into the load so the Pg is 1/4Rg not 1/8Rg.
;) tell your Prof you found a discrepancy, he might hire you for a job.
This is the MPT, but far from optimal efficiency but then is used in most RF with matched impedances.
I have never seen nor used his formula.