Acompany estimates its total profit (profit = total revenue minus total cost) as
p(x) = 2x5 − 3x4 − 5x2 − 2, where p is in thousands of dollars and x is the number of years elapsed since the company was founded. solve for the number of times the total profit become exactly zero. hint: use descartes's rule of signs.

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.