See attachment. Part (a) I say h is a function of t because the value of h depends on the value of t. So, t is the independent variable and h is the dependent variable. Part (b) The height of the projectile after 0.5 seconds is 20 feet. The height of the projectile after 1 25 seconds is 25 feet. Part (c) The domain of h is [0, 2.5]. Part (d) Part (a) above tells us that h is a function of t and not vice-versa. Part (a) also gives us a precise reason why t cannot be a function of h. You say? [ATTACH=full]60[/ATTACH]