Let A and B be subsets of Prove that (a) if A is bounded above and then B is bounded above.(b) if A is bounded below and then B is bounded below.(c) if A and B are bounded above, then is bounded above.(d) if A and B are bounded below, then is bounded below.

▯ Why was it invented Paintings of landscapes (especially middle class) – there was an interest and audience in photo for Interest in science, interest in people wanting to record things (especially botanists) Aesthetically, there was an increase in realistic paintings and photo is one step closer to reality 1839 = invention of photography ▯ Precursor to the invention of photography: camera obscura (meaning dark room) and it was basically a pinhole camera – the smaller the hole the better the Turns the image upside down Used as early as 17 century, they put paper on the wall opposite to the pinhole to create beautiful pictures of landscapes Many precursors to even th