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
Quasiperiodic function periodic functions and that article should be consulted. The more vague and general notion of quasiperiodicity has even less to do with quasiperiodic functions in the mathematical sense. A useful example is the function: If the ratio "A"/"B" is rational, this will have a true period, but if "A"/"B" is irrational there is no true period, but a succession of increasingly accurate "almost" periods. Quasiperiodic function In mathematics, a quasiperiodic function is a function that has a certain similarity to a periodic function. A function formula_1 is quasiperiodic with quasiperiod formula_2 if formula_3, where formula_4 is a ""simpler"" function than