HELP PLEASSEEE

In one day there are too high tides into low tides and equally spaced intervals the high tide is observed to be 6 feet above the average sea level after six hours passed a low tide occurs at 6 feet below the average sea level in this task you will model this occurrence using a trigonometric function by using x as a measurement of time assume the first high tide occurs at x=0. a. what are the independent and dependent variables? b. determine these key features of the function that models the tide: 1.amplitude 2.period 3.frequency 4.midline 5.vertical shift 6.phase shift c. create a trigonometric function that models the ocean tide for a period of 12 hours. d.what is the height of the tide after 93 hours?

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me

Combine like terms to create an equivalent expression. make sure to simplify coefficients and constants as well. -6/5-2/3v+4/15+1/3v