Answer:
(-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)
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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).
