human
Write a function to find the directrix of a parabola. Here is a solution in Python:
Give me a Python code to find the directrix of a parabola?
assistant
#Here is Python code to find the directrix of a parabola.
 def parabola_directrix(a, b, c): 
  directrix=((int)(c - ((b * b) + 1) * 4 * a ))
  return directrix