The tidal variation in Desolation Sound on the west coast of Canada is roughly 4 meters. That is, the difference beween water depth at high tide and at low tide is 4 meters, with successive high tides occurring 12.5 hours apart. Suppose that at Refuge Cove in Desolation Sound, the depth of water in meters is given by D(t) = D0 + Acos B(t - t0)

Find the value of a. the diagram is not to scale. a quadrilateral is drawn. the upper and lower sides are parallel. the interior angle in the upper left corner is labeled a degrees. the angle in the upper right corner is labeled 113 degrees. the angle in the lower right corner is labeled b degrees. the angle in the lower left corner is labeled 36 degrees. a. 36 b. 144 c. 54 d. 126

Which conjunction is disjunction is equivalent to the given absolute value inequality? |x+2|< 18

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?