The table gives a country's gross domestic product (GDP) (in trillions of doliars) for selected years from 2005 and projected to 2070 . Complete. parts (a) through (c) below. a. Find the best-fitting quadratic model for the data, with x equal to number of years after 2000 , y=11x2+11x+ (Type integers or decimals rounded to three decimal places as needed.)