Question

Which of the following could be the equation for a parabola that opens down with the vertex (-11,-28)?

Answer 1

Answer:y=-5(x+11)^2 -28

Step-by-step explanation: Okay think about what you know about translations and transformations of parent functions. In this case, the parent function is x2. So what now?

First, the problem states that the parabola opens DOWN. This means that you should look for a negative leading coefficient. This narrows your options down to C or D. (-5 is the leading coefficient)

Now starting with the x2, the vertex would be at (0,0), but in this problem it is at (-11,-28). That means it was TRANSLATED 11 spots in the negative x-direction and 28 spots in the negative y-direction.

Look at your options, when a number is being added directly unto the x variable, such as in answer C, it moves in the negative x-direction. This tells you that C has to be your answer.

I hope that helps!