For this case we have:
The equation in vertex form of the parabola is given by:
![y = a (x-h) ^ 2 + k\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/mp7ahzn62wfugu75u61aq5688laoent2to.png)
The vertex is (h, k) and is given by the highest or lowest point of the parabola, in this case it is observed that it is
![(h, k) = (- 3, -1)\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/5ka19m3roklkq8ma4xiz72qvkw2rluu8cx.png)
Thus, the equation is given by:
![y = a (x - (- 3)) ^ 2 + (- 1)\\\\y = a (x + 3) ^ 2-1\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/qkg57tlhpdhadir4ca5n9sipjed5hv58k8.png)
We look for the value of a, substituting a point of the parabola in the equation in the form of vertex, we will take the point
![(x, y) = (0,8)\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/dsjvmoc8hdm9edkqvafp0kudrqgfa09a8j.png)
Substituting we have:
![8 = a (0 - (- 3)) ^ 2 + (- 1)\\\\8 = a (0 + 3) ^ 2-1\\\\8 = a (3) ^ 2-1\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/vb5mfacpuxpbavexjkth0uzslk2v2z0wg4.png)
![8 = 9a-1\\\\8 + 1 = 9a\\\\9 = 9a\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/9a48fpm6tef3w90u5wadyko6yqzc37xs84.png)
![a = (9)/(9)\\\\a = 1\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/pxo2hi06nholunypqq7jh5ykv88alivv2n.png)
Thus, the equation of the parabola is given by:
![y = (x + 3) ^ 2-1\\](https://img.qammunity.org/2019/formulas/mathematics/high-school/ohzpxwe5632m17n5sevfe100fz8y9xxyo5.png)
Answer:
![y = (x + 3) ^ 2-1](https://img.qammunity.org/2019/formulas/mathematics/high-school/pj62tuwg61u7c1n2n73mizol2f12lri8aw.png)