(8) Let y = cost sin t. Find dy dt (9) According to the new unclassified U.S. Air Force report, radar began tracking the UFO at 21:37:12 Greenwich Mean Time. It was traveling at 50 mph, and its speed appeared to be increasing exponentially. At 21:37:17, its speed was recorded at 100 mph and still increasing exponentially. At 21:37:42, it vanished from the radar screen. If the UFO's speed had continued to increase exponentially throughout the tracking interval, what was its speed (to the nearest hundred mph) just before it vanished from the radar screen? (10) Find d y dx3' where y = 2ex* - 5x3.