It has taken me a long time to work out the function of ex-boyfriends, at least for me: how they can help you work out what you want from life and from a partner by showing you what you don't.… — Nicola Monaghan Copy Share Image
Who has not been amazed to learn that the function y = ex, like a phoenix rising from its own ashes, is its own derivative? — Francois Le Lionnais Copy Share Image
