set xrange [1e5:1e9]
set yrange [10:1e5]
set logscale xy
set xlabel "f/Hz"
set ylabel "X/Ohm"
plot 2*pi*x*1e-3 lw 5 title "1 mH" , 2*pi*x*1e-6 lw 5 title "1 µH" , 1/(2*pi*x*1e-9) lw 5 title "1 nF" , 1/(2*pi*x*1e-12) lw 5 title "1 pF"