2000 – 2019 by Gérard Michon. All scripts of the companion videos. Approach your problems from the right end and begin with the answers. Then one binary options trading graphs of trigonometric functions, perhaps, you will find the final question.
It’s better to know some of the questions than all of the answers. Whoever answers before pondering the question is foolish and confused. Proof by inspection for finitely applicable statements. Only a negative deserves a proof.