Write a cosine function that has a midline of 3, an amplitude of 5 and a period of 2

Choose a second initial value that is 0.01 greater than the initial value from question 9. iterate it using the function, f, ten times. if necessary, you can round your results to the nearest ten-thousandth.

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Can someone me out here number 4 plz