The Power $P$ In Watts (W) in a Circuit with Resistance $R$

Short Answer

The power $P$ in watts (W) in a circuit with resistance $R$ in ohms $(\Omega)$ varies according to $\mathrm{P}=\frac{49 \mathrm{R}}{(\mathrm{R}+9)^{2}}$ . Find the resistance that gives the maximum power.