20250429

159-1.py

@@ -0,0 +1,20 @@
+def fx(x):
+    return x**4-3*x+1
+
+
+def SolveByDivTwo(x1,x2,err):
+    while abs(x2-x1) >= err:
+        x = (x1+x2)/2
+        if fx(x) * fx(x1) < 0:
+            x2 = x
+        else:
+            x1 = x
+    return (x1+x2)/2
+
+
+if __name__ == "__main__":
+    x1 = 0.3
+    x2 = 0.4
+    err = 0.5e-5
+    root = SolveByDivTwo(x1, x2, err)
+    print(f"Root: {root:.5f}")