In which step below does a mistake first appear in simplifying the expression 0.5 (-12 + 6) - 3(c + 4) + 10(c - 5)? step one: -6c + 3 - 3(c +4) + 10(c - 5) step two: -6c + 3 - 3c - 12 + 10(c - 5) step three: -6c + 3 - 3c - 12 + 10c - 50 step four: 7c - 41 a: step 1 b: step 2 c: step 3 d: step 4

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?