Question 110773
Without doing any math we can answer all these questions.
x=-2 is the only answer. The axis of symmetry is also -2.
The vertex is (-2,0). And it has a maximum.
How do we know this? (x+2)^2=0 at the x intercept.
The answer is x=-2, x=-2.
So the vertex touches the y=0 line.
Does it point up or down?
Up. How do we know that? -3 is a negative number. If a is a negative number we have a maximum.
Ed
{{{graph(500,500,-10,10,-10,10,-3(x+2)^2)}}}