Chapter 11 - Section 11.6 - Further Graphing of Quadratic Functions - Exercise Set - Page 820: 18

Vertex: $(0, -1)$ Opens upward x-intercept:-1, 1 y-intercept: -1

$f(x)=x^2-1$ $f(x)=(x-1)(x+1)$ $a=1$, $b=0$, $c=-1$ Vertex: $x=-b/2a$ $x=-0/2*1$ $x=0$ $x=0$ $f(x)=x^2-1$ $f(0)=0^2-1$ $f(0)=0-1$ $f(0)=-1$ Vertex: $(0, -1)$ Opens upward $y=0$ $f(x)=(x-1)(x+1)$ $0=(x-1)(x+1)$ $0=x-1$ $0+1=x-1+1$ $1=x$ $0=x+1$ $0-1=x+1-1$ $-1=x$ $x=0$ $f(x)=x^2-1$ $f(0)=0^2-1$ $f(0)=0-1$ $f(0)=-1$ x-intercept:-1, 1 y-intercept: -1