Chapter 4 Quadratic Functions and Factoring - 4.10 Write Quadratic Functions and Models - 4.10 Exercises - Skill Practice - Page 312: 4

$y=-2(x+2)^{2}+1$

We already know $y$, $x$, $k$ and $h$ from the given vertex and point, so in order to get the quadratic function we need to find $a$... $y=a(x-h)^{2}+k$ $-1=a(-1+2)^{2}+1$ $-2=a(1)^{2}$ $a=-2$ Therefore the function is... $y=-2(x+2)^{2}+1$