Proposition 6.1.7: Properties for limits of Functions
If f(x)
exists, the limit is unique.
[ f(x) + g(x) ] = f(x) + g(x), provided that f(x) and g(x) exist.
[ f(x) g(x) ] = f(x) g(x), provided that f(x) and g(x) exist.
[ f(x) / g(x) ] = f(x) / g(x), provided that f(x) and g(x) exist and g(x) # 0.