Heidi bought a machine that throws tennis balls for her dog

Last updated: 7/12/2022

Heidi bought a machine that throws tennis balls for her dog to fetch. The height of each ball thrown by the machine, in feet, is modeled by the function f(x) = - x² + x + 2, where x represents time in seconds. How many seconds after the machine throws the ball does it hit the ground? 1 second 3 seconds 4 seconds 2 seconds