import numpy as np
import matplotlib.pyplot as plt

def u(x,p):
    return (np.exp(p*x) - 1)/(np.exp(p) - 1)

x = np.linspace(0, 1, 200)


plt.figure(figsize=(8, 5))
for p in [ -3, -1, -0.5, 0.5,  2,  4]:
    plt.plot(x, u(x, p), label="p ="+ str(p))

plt.xlabel('x')
plt.ylabel('u(x)')
plt.legend()
plt.grid(True)
plt.show()