Brenna's mom, Mrs. Herstone, is watching Brenna playing at the park. Some children are pushing Brenna on the merry-go-round. Mrs. Herstone decides to take some data, so she starts her stopwatch. At 0.5 seconds Brenna is farthest from Mrs. Herstone, 26 feet away. When the stopwatch reads 4.2 seconds, Brenna is closest at 12 feet away. Write a periodic function that models the distance Brenna is from Mrs. Herstone over time if the merry-go-round is spinning at a constant rate.