10 DEFFNA(X)=X*X*X-2*X*X+7
20 DEFFNB(X)=X*X+7*X
30 GE=5:REM GENAUIGKEIT
40 DE=0.5/10^GE
50 INPUT"STARTWERT";XA
60 X=XA
70 FA=FNA(X)-FNB(X)
80 X=XA+0.1
90 F=FNA(X)-FNB(X)
100 XN=X-(XA-X)*F/(FA-F)
110 D=ABS((X-XN)/(XN+DE))
120 IFD<DETHEN140
130 X=XN:GOTO90
140 PRINT"X=";XN