7. [-/1 Points] DETAILS SPRECALC7 2.1.031. Evaluate the piecewise defined function at the indicated values. 1( x ) = 1x 2 if x 1 f ( - 3 ) = (- 3) = f ( - 1) = f(0) = f(45) =9. [-/1 Points] DETAILS SPRECALC7 2.1.079.MI. A tank holds 90 gal of water, which drains from a leak at the bottom, causing the tank to empty in 28 min. The tank drains faster when it is nearly full because the pressure on the leak is greater. Toricelli's Law gives the volume of water remaining in the tank after t minutes as V(t) = 90(1 - Osts 28. (a) Find V(0) and V(28). V(0) = gal V(28) = gal (b) What do your answers to part (a) represent? V(0) represents the time when the tank is empty, and V(28) represents the time when it is full. O V(28) represents the the time when the tank is empty, and V(0) represents the time when it is full. V(28) represents the initial volume, and V(0) represents the final volume. V(0) represents the initial volume, and V(28) represents the final volume. V(0) represents the initial rate at which the water is leaking, and V(28) represents the rate at which it is leaking when 28 gallons have drained. (c) Make a table of values of V(t) for t = 0, 7, 14, 21, 28. (Round your answer to three decimal places.) t (in minutes) V(t) (in gallons) 0 14 21 28 (d) Find the net change in the volume V as t changes from 0 min to 28 min. gal 10. [-/1 Points] DETAILS SPRECALC7 2.1.086. An Internet bookstore charges $15 shipping for orders under $100 but provides free shipping for orders of $100 or more. The cost C of an order is a function of the total price x of the books purchased, given by (x) = x + 15 if x