Answer:
Explanation:
SInce the distance between the vertex and the focus is the same as the distance from the vertex to the directrix, the distance from the directrix to the focus is 22‾√.
Since the shortest path from the focus to the directrix goes through the vertex, the distance from the focus to the directrix is the sum of the distance from the focus to the vertex and the distance of the vertex to the directrix, namely 22‾√+22‾√=42‾√