engineers are designing a roller coaster that at one point goes underground. The roller coasters path underground is a large curve. The engineers use function shown to model the elevation, E, in feet and T, time, in seconds, all the roller coasters path while it is underground EE(t) = t2 – 10t + 16

Part A: write an equivalent form of E(t) that can be used to find the time when the world coaster goes underground and the time the roller coaster returns above ground
E(t)=_

Part B: how long, in seconds, was the roller coaster underground?