# How do you write y = x^2 - 2x -3 into vertex form?

x of vertex: $x = \left(- \frac{b}{2} a\right) = \frac{2}{2} = 1$
y of vertex: y = (f(1) = 1 - 2 - 3 = -4
Vertex form: $f \left(x\right) = {\left(x - 1\right)}^{2} - 4$
Check by developing: $f \left(x\right) = {x}^{2} - 2 x + 1 - 4$ . OK