how to plot multiple functions in the same plot

You can use matplotlib to plot multiple functions on the same graph, there are several ways of achieving this.

One of the easiest ways is as shown

import matplotlib.pyplot as plt
import numpy as np


# I will make up sample values of t
t = np.arange(1, 30, 2) # [1, 3, 5, ..29 1 to 29 increment by 2 

A = 6 / ( 4+ t ** 2) # function 1
B = 6 / ( 4 + t ** 3) # function 2
C = 18/( 3 * t) # making up random function here as function 3

# red dashes, blue squares and green triangles
# think of this as (x, y , color/symbols)

plt.plot(t, A, 'r--', t, B, 'bs', t, C, 'g^')
plt.show()

You should have something like this