First, let's list the roots, we can see in the graph that it's
We can see that the graph crosses the x-axis on all roots then they all have simple multiplicity (1). Then we know that the polynomial is something like
We can find the domain and the range graphically, we know that polynomial functions do not have any domain restriction, therefore
For the range, we must see which values the polynomial can take, usually, even powered polynomials have a restricted range, here the degree is 4, then it must be restricted.
We can see in the graph that the function does not take any value under -16, therefore the range is
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Now to find the equation, let's remember that
We do not have the value of "a", but we know that when x = 0 we have y = 9, we can use that to find a
Therefore the equation is
We can also do the distributive