How do I factor this?

cos^4x - sin^4x

Jayda's house is located at (1, 5). she can walk in a straight line to get to cristian's house. a fast-food restaurant is located at (11, 0) and partitions the way from jayda's house to cristian's house by a ratio of 5: 1. find the coordinate of cristian's house. me . im a little stuck

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?

Sasha drank 8 bottles of water everyday for a week. how many bottles of water did she drink in total?