Continuous Function BCOR-120 Automn 2011 for all x from the open interval (x 0 −δ, x 0 +δ) the function values f (x) are within the open interval (f (x 0 ) − ε, f (x 0 ) + ε)
Discontinuous Function BCOR-120 Automn 2011 There exist a least an x from the open interval (x 0 −δ, x 0 +δ) For which the function values f (x) is outside the open interval (f (x 0 ) − ε, f (x 0 ) + ε)
This notion deals with the question of which value does the dependent variable y of a function f with y = f (x) approach as the independent variable x approaches some specific value x0?
In the above definition, the elements of sequence { x n } can be both greater and smaller than x 0 . In certain situations, only the limit from one side has to be considered. In the following, we consider such one-sided approaches, where the terms of the sequences are either all greater or all smaller than x 0 .
If we apply Theorem 4.2, part (4), and separately determine the limit of the numerator and the denominator, we find that both terms tend to zero, and we cannot find the limit in this way. Therefore, we rationalize the numerator by multiplying the numerator and the denominator by √ x + 2 and obtain: