5 PRINT 
10 PRINT "FINDS ROOT OF AN EQUATION OVER THE INTERVAL [A,B]"
20 PRINT " BY METHOD OF SUCCESSIVE BISECTION"
30 PRINT 
40 PRINT "EQUATION MUST BE INSERTED AS STATEMENT 50,"
45 PRINT " IN THE FORM : 50 DEF FNG(X) = ..."
50 DEF FNG(X) = (X*X-5)*X-1
60 PRINT 
70 PRINT "INPUT A,B,TOLERANCE"
80 INPUT A,B,T
90 LET N=0
110 LET X2=B
120 LET N=0 : X1=A : X2=B : Y1=FNG(X1)
130 IF Y1*FNG(X2)<0   GO TO 200
140 N=1 : GO TO 400
200 LET X5=(X1+X2)/2
210 IF ABS(X1-X2)<T   GO TO 350
220 IF Y1*FNG(X5)=0   GO TO 350
230 IF Y1*FNG(X5)<0   GO TO 250
240 X1=X5 : GO TO 200
250 X2=X5 : GO TO 200
350 R=X5
400 IF N=0   GO TO 450
410 PRINT "FUNCTION VALUES AT END POINTS HAVE SAME SIGN,"
420 PRINT " METHOD IS INAPPLICABLE FOR THIS INTERVAL"
430 GO TO 60
450 PRINT "ROOT IS",R
460 PRINT " VALUE OF FUNCTION AT ROOT IS",FNG(R)
470 GO TO 60
480 END