For what value(s) of t, with 0 ≤ t ≤ 4, is the slope of the curve undefined for the graph defined by x = 2t - 2 sin(t), y = 2 - 2 cos(t) ? Type your answer in the space below to the nearest whole number. (ex: 4)

Melanie is buying a bathing suit that costs 39.99. she is given a discount at the cash register of $6.00 when she scratched 15% off on a game piece for a store promotion. what will the sale price of melanie’s bathing suit be?