Level 3.2 : y = sqrt(abs(x))

# 作図方法
gnuplot<<EOF
clear
plot sqrt(abs(x))
set grid
set xlabel "x"
set ylabel "y"
set title "y = sqrt(abs(x))"
set terminal png
set output "func3_2.png"
replot
set terminal svg
set output "func3_2.svg"
replot
set terminal pdf
set output "func3_2.pdf"
replot
EOF