Given cos u = - 2/(sqrt(5)) and pi/2 < u < pi, evaluate the following using the double-angle formulas: sin2u=, cos2u=, and tan2u=

Jermaine has t subway tokens. karen has 4 more subway tokens than jermaine. raul has 5 fewer subway tokens than jermaine. which expression represents the ratio of karen's tokens to raul's tokens

Adolphin is swimming with her friend. the dolphin jumps to a height of 4.54.54, point, 5 meters above the surface of the water as her friend swims 9.89.89, point, 8 meters directly below her. what is the position of the dolphin's friend relative to the surface of the water? meters

Acompany makes steel lids that have a diameter of 13 inches. what is the area of each lid? round your answer to the nearest hundredth