#!/usr/bin/perl

use warnings;
use strict;

my $y    = $ARGV[0];
my $t0   = $ARGV[1];
my $dt   = $ARGV[2] || 0.01;
my $tmax = $ARGV[3] || 1;

for(my $t = $t0; $t <= $t0 + $tmax; $t += $dt) {
    print "$t\t$y\n";

    # my $dy = -2*$t*$y / ($y**2 + $t**2 + 1) * $dt;
    my $dy = $t / $y * $dt;
    $y += $dy;
}