A large tank is designed with ends in the shape of the region between the curves y=(x-squared)/2 and y=12, measured in feet. Find the hydrostatic force on one end of the tank if it is filled to a depth of 8 ft with gasoline. (Assume the gasoline's density is 42 lb/cubic feet.) So far I have graphed y=12 and y= 1/2 x^2. I set up my integral as the integral of 42 x (8-x) x Area dx, but I am not sure if I am doing this correctly. How would I get the area?