Learn the differences between the 83 and 86 before attempting something like this. See the fully corrected text below: >PROGRAM:TRIGFUNC >:FnOff >:Radian >:ZTrig >:Disp "Y=Asin(Bx + C) + D" >:Prompt A,B,C,D >:y1=A*sin(B*x+C)+D >:DrawF y1