numerical method

num_method.rb

def f(x)
  x**3 - 0.2 * x**2 - 0.2 * x - 1.2
  # x**4 + 2 * x**3 - x - 1
end

def calc(x_min, x_max, old = 9999, accuracy = 0.0001)
  found_x = (x_min + x_max) / 2
  p found_x
  val = f((x_max + x_min)/2)
  return found_x if (old - found_x).abs < accuracy

  if val == 0
    return found_x
  else
    if f(x_min) * f(found_x) < 0
      calc(x_min, found_x, found_x)
    elsif f(found_x) * f(x_max) < 0
      calc(found_x, x_max, found_x)
    end
  end
end


p calc(1.0, 2.0)