By definition, a Quadratic function written in Standard form, is:
[tex]y=ax^2+bx+c[/tex]Where "a", "b" and "c" are Real numbers (the lead coefficient "a" cannot be zero).
For this case, you have the following Quadratic function written in Vertex form:
[tex]f(x)=(x-2)^2-3[/tex]By definition, you have that:
[tex](a-b)^2=a^2-2ab+b^2[/tex]Then, applying that formula, you can simplifiy the function and write it in Standard form:
[tex]\begin{gathered} f(x)=(x^2-2(x)(2)+2^2)-3 \\ f(x)=x^2-4x+4-3 \\ f(x)=x^2-4x+1 \end{gathered}[/tex]Therefore, the answer is:
[tex]f(x)=x^2-4x+1[/tex]