To determine the coordinates of the vertex of a concave down parabola based on the description provided, it typically lies at its maximum. Given that it passes through the 1st, 3rd, and 4th quadrants, we can infer that the vertex would be located in the 2nd quadrant since it is concave down.
However, I don't have the actual image to visualize the exact position. If you provide specific context or coordinates related to the vertex or other points on the parabola, I can assist further. Otherwise, based on your description, please mention the coordinates as they appear on the graph.