The given point is (2,1), and the vertex is (4, -2). This means h = 4, and k = -2.
To find the equation, we have to find the parameter a with the given information and the vertex form.
Let's replace the given point and the vertex.
Now, we replace the parameter a and the vertex to find the equation of the parabola.
The image below shows the parabola.
The function would be