The sum of four and twelve is??

What is the value of x in the following equation. -x ^3/2 = -27

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.

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)