380 "S" CLEAR : CLS : INPUT "Start=";X#,"n=";Q:E#=1E-9: FOR I=1 TO Q:A#=E#: IF  ABS X#>E# LET A#=X#*E#
  381 GOSUB 1:B#=F#:X#=X#+A#: GOSUB 1:A#=-F#*A#/(F#-B#):X#=X#+A#:C#= ABS X#: IF C#<=1 LET C#=1
  382 IF I=Q PRINT "too slow": GOTO 385
  383 IF  ABS A#<E#*C# OR  ABS F#<E# THEN 385
  384 NEXT I
  385 PRINT "x=";X#: GOSUB 1: PRINT "f(x)=";F#: END