[EQ] P_{max} = \frac{|V_{g}|^{2}}{8R_{1}} = 0.125 W\\ 0.1·0.125 W = 12.5 mW\\ P_{md-R_{2}} = \frac{|I|^{2}R_{2}}{2} = 0.0125 => R_{2} = 3.8\mbox{kOhm\ ó\ }2.63 \mbox{Ohm}\ \mbox{(Empiezo a sospechar que la he cagado xD)} [/EQ]