F(x)=x^2+x+5
then
F(3) would be the function evaluated at x=3, or 17.
anytime you see F(3) it is just whatever formula you are looking at evaluated when the variable is equal to 3.
We could put the domain into the x values to get the y values (range).
y = 3(-3) - 4
y = -9 - 4
y = -13
y = 3(-1) - 4
y = -3 - 4
y = -7
y = 3(4) - 4
y = 12 - 4
y = 8
