
fr=!random 1.5,2.5
amp=!random 1,2
amp=$[$amp/$fr]

ph=!random 0,2*pi
amp=!randitem $amp,-$amp

f=$amp*sin($fr*x+$ph-pi/2)
der=$amp*$fr*sin($fr*x+$ph)
root=-$ph/$fr,(pi-$ph)/$fr

