111

159-5.py

@@ -1,6 +1,6 @@
 import math
 
-
+#原函数和导数改成题干的形式#####################
 def f1(x):
     return x**2 + 10*math.cos(x)
 
@@ -17,12 +17,14 @@ def df2(x):
 # 牛顿方法求解方程
 def NewtonSolve(fx, dfx, x0, err, N0):
     count = 0
+    print(f"k={count}, x0={x0}")
     x1 = x0 + 1 + err
     while abs(x1 - x0) > err or abs(fx(x1)) > err: # 添加条件修正根误差太大的问题
         if abs(dfx(x1)) < 1e-10:
             return None, 0
         x1 = x0 - fx(x0) / dfx(x0)
         count += 1
+        print(f"k={count}, x{count}={x1},x1-x0={abs(x1-x0)}")
         if count > N0:
             return None, -1
         x0 = x1
@@ -41,6 +43,7 @@ if __name__ == "__main__":
     err = 1e-5
     N0 = 100
 
+#把初始值换成题干形式###############
     x0 = 1.6
     result,status = NewtonSolve(f1, df1, x0, err,N0)
     if status == 1:
@@ -51,7 +54,7 @@ if __name__ == "__main__":
         print("f1导数为0，无法收敛")
 
 
-    x0 = FindRootZone(f2, -5, 5, 0.01)
+    x0 = FindRootZone(f2, -5, 5, 0.01) # 查找f2的根区间与步长
     result, status = NewtonSolve(f2, df2, x0, err,N0)
     if status == 1:
         print(f"f2收敛 解为: {result}")