f(x) = x2 – 2x – 6 written in standard form. whar is this function written in vertex form? 1.f(x) = (x –1)2 – 7 2. f(x) = (x 1)2 – 7 3.f(x) = (x –1)2 – 5 4.f(x) = (x 1)2 – 5