习题2.1

import numpy as np  
import matplotlib.pyplot as plt  
  
# 定义 x 的范围  
x = np.linspace(-5, 5, 400)  
  
# 计算三个函数的值  
y_cosh = np.cosh(x)  
y_sinh = np.sinh(x)  
y_half_exp = 0.5 * np.exp(x)  
  
# 创建图形和坐标轴  
plt.figure(figsize=(10, 6))  
ax = plt.gca()  
  
# 绘制函数  
ax.plot(x, y_cosh, label=r'$y = \cosh(x)$', color='blue')  
ax.plot(x, y_sinh, label=r'$y = \sinh(x)$', color='green')  
ax.plot(x, y_half_exp, label=r'$y = \frac{1}{2}e^x$', color='red')  
  
# 添加图例  
plt.legend(loc='upper left')  
  
# 添加网格  
plt.grid(True)  
  
# 设置标题和坐标轴标签  
plt.title('Plot of $\cosh(x)$, $\sinh(x)$, and $\frac{1}{2}e^x$')  
plt.xlabel('x')  
plt.ylabel('y')  
  
# 显示图形  
plt.show()
 
print("学号：3008")

结果如下图