Fear of flying persistent fear or anxiety when they consider flying, as well as during flying. They will avoid flying if they can, and the fear, anxiety, and avoidance cause significant distress and impair their ability to function. Take-off, bad weather, and turbulence appear to be the most anxiety provoking aspects of flying. The most extreme manifestations can include panic attacks or vomiting at the mere sight or mention of an aircraft or air travel. Around 60% of people with fear of flying report having some other anxiety disorder. The causes of flight phobia and the mechanisms by which it is maintained were
Proof that π is irrational connection between the proofs lies in the fact that Hermite already mentions that if "f" is a polynomial function and then from which it follows that Bourbaki's proof is outlined as an exercise in his calculus treatise. For each natural number "b" and each non-negative integer "n", define Since "A"("b") is the integral of a function which defined on [0,] that takes the value 0 on 0 and on and which is greater than 0 otherwise, "A"("b") > 0. Besides, for each natural number "b", "A"("b") < 1 if "n" is large enough, because and therefore On the other hand,