1) "Prove ." (This is very first workbook exercise for our Real (and Complex) analysis.)
I have more: 2) "Prove that if " and prove that 3) "square of every negative number is a positive number".
I presume that the more elementary it is, the harder it is (like Principia proving that 1+1=2 (after how many pages?))?
How many ways can such be proven (I think we've done it in discrete math, but workbook is from analysis)?