What is the solution set of –x2 – 6 < 0?

the answer is the longer one with parenthesis

(-4,-21)

Step-by-step explanation:

Apply the formula for calculate the x-coordinate of the vertex of the parabola:

Where:

a=1 and b=8

Then, this is:

Now you must substitute x=-4 into the function to obtain the y-coordinate of the vertex.

Then, this is:

Therefore the vertex is:

(-4,-21)