The standard form of a quadratic function is [tex]f(x) = ax^2+bx+c[/tex]. To convert from vertex form to standard form, first expand the squared term to get [tex](x+2)^2=x^2+4x+4[/tex] (hint: use foil to expand binomials). Then, simplify by combining like terms.
[tex]f(x)=x^2+4x+4-3=x^2+4x+1[/tex].