arcsin(x)
Under systemd

runlevel -> systemd target
0 poweroff.target
1 rescue.target
2,3,4 multi-user.target
5 graphical.target
6 reboot.target

to change runlevels under systemd

$ sudo systemctl isolate <TARGET>

to change the default

$ sudo systemctl enable <TARGET>
$ sudo systemctl set-default <TARGET>


logins on virtual terminal:

sudo systemctl enable multi-user.target &&  systemctl set-default multi-user.target