The focus of the parabola - 40x = y 2 is: (-10, 0) (10, 0) (0, 10) (0, - 10)

(-10, 0)

Step-by-step explanation:

The parabola opens to the left, and its vertex is at (0, 0). The focus must have an x-coordinate that is negative. The only viable choice is ...

(-10, 0)

__

The equation is in the form ...

4px = y^2

where p is the distance from the vertex to the focus.

In the given equation, 4p = - 40, so p=-10, and the focus is 10 units to the left of the vertex. In this equation, the vertex corresponds to the values of the variables where the squared term is zero: (x, y) = (0, 0).