def show_negative_point(self):
    v_line = self.get_vertical_line_to_graph(self.sample_input, self.graph, color=RED)
    self.play(ShowCreation(v_line))
    self.wait()
    self.v_line = v_line
def show_negative_point(self):
    v_line = self.get_vertical_line_to_graph(self.sample_input, self.graph, color=RED)
    self.play(ShowCreation(v_line))
    self.wait()
    self.v_line = v_line