The standard form:
[tex]y=ax^2+bx+c[/tex]
We have [tex]y=(x-1)^2-1[/tex]
Use [tex](a-b)^2=a^2-2ab+b^2[/tex]
[tex]y=x^2-2(x)(1)+1^2-1\\\\y=x^2-2x+1-1\\\\\boxed{y=x^2-2x}\\\\a=1,\ b=-2,\ c=0[/tex]