This may be rephrased as: the value of f (x) may be made larger than any given
number by choosing a positive real number very close to 0 In symbols, we write
lim0
( )
x
f x
→+
= + ∞
(to be read as: the right hand limit of f (x) at 0 is plus infinity) We wish to emphasise
that + ∞ is NOT a real number and hence the right hand limit of f at 0 does not exist (as
a real number) Similarly, the left hand limit of f  at 0 may be found