Vertex form uses the following formula:
![a(x-h)^2 + k](https://img.qammunity.org/2019/formulas/mathematics/high-school/mo1uvlmqenbg4im16sdlwzj7bpycwdfe8k.png)
a determines the stretch of the parabola. h and k are the x and y values of the vertex (h, k), respectively.
The vertex is at (-1, 0). There is no a value indicated for any answer. Plug these values into the equation:
![\text{h = -1, k = 0}](https://img.qammunity.org/2019/formulas/mathematics/high-school/km3gpalk8rjl9tzgb4bjc6r48luqph32vk.png)
![(x - (-1))^2 + 0](https://img.qammunity.org/2019/formulas/mathematics/high-school/adr9mgtipo0y6iiu25hiwnvxr188p3gypi.png)
![\boxed{(x+1)^2}](https://img.qammunity.org/2019/formulas/mathematics/high-school/l63xcz5lvgsa7496rpu7jfyxu9ipki2zju.png)
The answer is (x+1)^2.