import math as m
import matplotlib.pyplot as plt
import numpy as np

def g(x,t):
    return m.cos(t)/(x+t)

def rectangle(n,x):
    som = 0
    for k in range(n):
        som += g(x,k/n)
    return som / n

def graph():
    X = np.linspace(0.001,100,10000)
    Y = [rectangle(10000,x) for x in X]
    plt.plot(X,Y)
    plt.show()