L'hospital Rule And Differntiation
from sympy import *
x, y = symbols('x y')
n=(x ** 2 - 1)
d=(x ** 2 - x)
expr = n/d
print("Expression f(x): {}\nlimit f(x) x->0 = {}".format(expr,limit(expr,x,0)))
expr_diff = Derivative(expr, x).doit()
print("f'(x)=",expr_diff)
expr_diff = Derivative(expr_diff, x).doit()
print("f''(x)=",expr_diff)
r=t/k
print(r)
print("limit f(x) x->0 =",limit(r,x,0))