Answer
a)
Focus: $0,3$
Directrix: $y=-3$
Vertex: $0,0$
b)
Focus: $(3,0)$
Directrix: $x=-3$
Vertex: $(0,0)$
Work Step by Step
To find the focus on each graph, look for the red point directly above or next to the vertex (the red point at the base of the parabola.
The directrix is the blue line on the graph.
In "a,"
Your focus is (0,3), your vertex is (0,0). And your directrix is $y=-3$.
In "b,"
Your focus is (3,0), your vertex is (0,0). And your directrix is $x=-3$