Algebra-2

Question Analysis
This question involves finding an absolute value function using its vertex (on the y-axis) and a point on the graph.
The main focus is determining a in the simplified vertex form.

Key Concept Explanation
For a vertex at , the vertex form simplifies to , where a determines direction and stretch/compression.

Step-by-Step Solution
Vertex (0, 3) → , : .
Substitute (2, -1): →