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}")

159-3.py

@@ -0,0 +1,43 @@
+def fd1(x):
+    return 1+1/x**2
+
+def fd2(x):
+    return 1/(x-1)**0.5
+
+def Renew(x,fd,err):
+    count=0
+    i = 0
+    try:
+        while True:
+            xk = fd(x)
+            if abs(i) < (xk-x):
+                count += 1
+            else:
+                count = 0
+            if count > 10:
+                print("不收敛")
+                break
+            if abs(xk-x) < err:
+                return xk
+            i = xk-x
+            x = xk
+    except Exception as e:
+        print(f"发生错误: {e}")
+        return None
+    return None
+
+
+if __name__ == "__main__":
+    x0 = 1.5
+
+    result = Renew(x0, fd1, 1e-5)
+    if result is not None:
+        print(f"1式收敛 解为: {result:.5f}")
+    else:
+        print("1式不收敛")
+
+    result = Renew(x0, fd2, 1e-5)
+    if result is not None:
+        print(f"2式收敛 解为: {result:.5f}")
+    else:
+        print("2式不收敛")