Answer:
[tex]y=\frac{1}{2}(x-4)^2+13\text{ }\operatorname{\Rightarrow}(A)[/tex]
Explanation: We have to find the vertex form of the parabola equation from the given standard form of it:
[tex]y=\frac{1}{2}x^2-4x+21\rightarrow(1)[/tex]
The general form of the vertex parabola equation is as follows:
[tex]\begin{gathered} y=A(x-h)^2+k\rightarrow(2) \\ \\ \text{ Where:} \\ \\ (h,k)\rightarrow(x,y)\Rightarrow\text{ The Vertex} \end{gathered}[/tex]
Comparing the equation (2) with the original equation (1) by looking at the graph of (1) gives the following:
[tex](h,k)=(x,y)=(-4,13)[/tex]
Therefore the vertex form of the equation is as follows:
[tex]y=\frac{1}{2}(x-4)^2+13\Rightarrow(A)[/tex]
Therefore the answer is Option(A).
