1: there are 11 rows of seats in a concert hall: 15 seats are in the 1st row, 18 seats in the 2nd row, 21 seats in the 3rd row, and so on. what's the explicit equation and the recursive equation?

2: if the price per ticket is 27$, how much will be the total sales for a one-night concert if all the seats are taken?

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?