Plz plz plz help

Find the value of the cosine for angle a

The height of a flare fired from the deck of a ship in distress can be modeled by h(t)= -2(8t^2-52t-28), where h is the height of the flare above water and t is the time in seconds. a. find the time it takes the flare to hit the water.

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')