Fear of needles to the phobic imagining the procedure being performed on themselves. Recent neuroscience research shows that feeling a pin prick sensation and watching someone else's hand get pricked by a pin activate the same part of the brain. Fear of needles, especially in its more severe forms, is often comorbid with other phobias and psychological ailments; for example, iatrophobia, or an irrational fear of doctors, is often seen in needle phobic patients. A needle phobic patient does not need to physically be in a doctor's office to experience panic attacks or anxiety brought on by needle phobia. There are many triggers
Irrational number the coefficients formula_7 are integers and formula_8. Any rational root of this polynomial equation must be of the form "r" /"s", where "r" is a divisor of "a" and "s" is a divisor of "a". If a real root formula_9 of a polynomial formula_10 is not among these finitely many possibilities, it must be an irrational algebraic number. An exemplary proof for the existence of such algebraic irrationals is by showing that "x" = (2 + 1) is an irrational root of a polynomial with integer coefficients: it satisfies ("x" − 1) = 2 and hence "x" − 2"x" −