10 INPUT "Range: ",L
20 PRINT "N    ISQR ASQR         SQR          SQR-ASQR     (SQR-ASQR)/SQR "
100 FOR X=1 TO L
110 GOSUB 1000
115 GOSUB 1200
120 PRINT #4,X,S,#12,A,SQR(X),SQR(X)-A,(SQR(X)-A)/A
140 NEXT X
999 END
1000 REM "Find the closest integer square root"
1010 FOR I=1 TO 1000
1020 IF I*I>X THEN S=I-1 ELSE  GOTO 1030
1025 IF I*I-X<X-S*S THEN S=I
1026 RETURN
1030 NEXT
1050 RETURN
1200 REM "Approximate the root with first order taylor"
1220 A=S+(X-S*S)/S/2
1230 RETURN