Equation of parabola is
.
Explanation:
The vertex form of the parabola is given as,
![y=a(x-h)^(2)+k](https://img.qammunity.org/2021/formulas/mathematics/college/1tdyfe7q56d7n6ane719pud03somri7y0l.png)
where (h,k) is the vertex of the parabola.
If the parabola must be symmetric about x = -10 then the axis of symmetry must be x = -10.
To execute this, h should be -10, and it was plugged in the vertex form of the parabola, a and k may be any real number.
So the equation can be written as,
![y=(x+10)^(2)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/xriuxqamy563l6j45zs96j65jmon82yhb4.png)