m=fef0m=\frac{f_{e}}{f_{0}}m=f0fe
m=f0fem=\frac{f_{0}}{f_{e}}m=fef0
m=f0fe(1+feD)m=\frac{f_{0}}{f_{e}}\left(1+\frac{f_{e}}{D}\right)m=fef0(1+Dfe)
m=fef0(1+feD)m=\frac{f_{e}}{f_{0}}\left(1+\frac{f_{e}}{D}\right)m=f0fe(1+Dfe)