At the state fair, Erin and her cousin ride the Ultra Drop roller coaster. When the ride plummets down the first hill, it dips below the loading platform. At the bottom, a camera snaps the riders' picture before hurtling them back toward the sky.

The equation y = x2 - 9x + 20 models the roller coaster's path over time. The variable y represents height (in feet) above or below the platform. At y = 0, the roller coaster is even with the platform. The variable x represents the amount of time (in seconds) since the ride began.

b. What is the height and time at which Erin's picture is taken during the roller coaster ride? Hint: Erin's picture is taken at the lowest point of the roller coaster.