text: # -*- coding: utf-8 -*-
  from sympy import symbols, latex
  from sympy.plotting import plot
  
  n = symbols('n')
  exp_0 = 0.5*(n*n)-3*n
  exp_1 = n*n
  p1 = plot(exp_0, exp_1, (n, 0, 13), legend=True, show=False)
  p1[1].line_color = 'r'
  p1[0].label = f'${latex(exp_0)}$'
  p1[1].label = f'${latex(exp_1)}$'
  p1.show()
  