Engineers are designing a rollercoaster that at one point goes underground. The rollercoaster's path underground is a large curve. The engineers use the function shown to model the elevation, E, in feet and t, time, in seconds, of the rollercoaster's path while it is underground. E(t)=t^2-10t-16
Part A: Write an equivalent form of E(t) that can be used to find the time when the rollercoaster goes underground and the time the rollercoaster returns above ground.
Part B: How long, in seconds, was the rollercoaster underground?
Please show the work to find the answer, ill love, you forever and I'll give you a cookie.