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REM 方程式の解の近似(2分法) f(x)=x^2-2=0
LET a=1
LET b=2
DEF f(x)=x^2-2
FOR k=1 TO 100
   LET x=(a+b)/2
   IF f(x)<0 THEN LET a=x
   IF f(x)>0 THEN LET b=x
   IF f(x)=0 THEN EXIT FOR
NEXT k
PRINT x
PRINT SQR(2)
END
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REM 方程式の解の近似(Newton法) f(x)=x^2-3=0
LET b=2
DEF f(x)=x^2-3
DEF f1(x)=2*x
LET x=b
FOR k=1 TO 15
   LET x=x-f(x)/f1(x)
NEXT k
PRINT x
PRINT SQR(3)
END
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REM 方程式の解の近似(セカント法) f(x)=x^2-3=0
DEF f(x)=x^2-3
LET x0=1
LET x1=2
FOR k=1 TO 20
   IF f(x1)-f(x0)=0 THEN
      EXIT FOR
   else
      LET x2=x1-f(x1)*(x1-x0)/(f(x1)-f(x0))
      LET x0=x1
      LET x1=x2
   END IF
NEXT k
PRINT x2
PRINT SQR(3)
END
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REM 方程式の解の近似(2分法と改良2分法) f(x)=x^2-3=0
DEF f(x)=x^2-3
LET a=1
LET b=2
FOR k=1 TO 20
   LET x=(a+b)/2
   IF f(x)<0 THEN LET a=x
   IF f(x)>0 THEN LET b=x
   IF f(x)=0 THEN EXIT FOR
NEXT k
PRINT x
LET a=1
LET b=2
FOR k=1 TO 20
   LET x=a-f(a)*(b-a)/(f(b)-f(a))
   IF f(x)<0 THEN LET a=x
   IF f(x)>0 THEN LET b=x
   IF f(x)=0 THEN EXIT FOR
NEXT k
PRINT x
END
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