reset set border set xtics 0.01 set ytics 0.01 set xzeroaxis lt 9 lw 5 set yzeroaxis lt 9 lw 5 set style line 1 lt 1 lw 4 set style line 2 lt 3 lw 5 set style line 3 lt 10 lw 6 set style line 4 lt 12 lw 3 set style line 5 lt 9 lw 1 set grid ls 5 show grid set xrange [11.9:12.1] set yrange [-7.3:-7.2] set samples 1000 set key on f(x)=-0.75*x+1.75 g(x)=-0.5*x-1.25 h(x)=f(x)/g(x) # i(x)=4*x**2+40*x+84 # plot f(x) ls 1 # plot f(x) ls 1,g(x) ls 2, h(x) ls 3, i(x) ls 4 plot f(x) ls 1,g(x) ls 2