17. Domain is all real numbers because the equation has a y-value for all x-values as far as we can see with the information given.
18. Range is 3< y <8, because the equation only has values for x where y is between those numbers.
19. Range is 3> y >-∞ (negative infinity) because the parabola's vertex has a y-coordinate of 3 and the parabola goes on forever in the negative direction (as seen by the arrows).
20. Domain is -∞ < x < 4 because the parabola's vertex has an x-coordinate of 4 and goes on forever in the negative x direction.
