upd

exam/archive/scripts/4.py

@@ -0,0 +1,17 @@
+import numpy as np
+import matplotlib.pyplot as plt
+
+r = 1.0
+
+R = np.linspace(0.001, 10, 500)
+
+eta = R / (R + r)
+
+plt.plot(R, eta)
+plt.xlabel("R")
+plt.ylabel("η(R)")
+plt.grid(True)
+
+plt.savefig("4.png", dpi=300, bbox_inches="tight")
+plt.show()
+