Answer:

Step-by-step explanation:
First off, <em>B</em><em> </em>is zero, so there is no <em>phase </em>shift, meaning that the vertex stays on the y-axis. Next, <em>A</em><em> </em>is negative, so the parabola opens down, and whenever you have a parabola opening down, it does so at maximum. Finally, <em>C</em><em> </em>represents our y-intercept, or in this case, our <em>vertical</em><em> </em><em>shift</em>.<em> </em>Our y-intercept is (0, −1), and so as our vertex, hence our answer.
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