Limits of Functions : Prove (using the definitions of the limit at infinity and at a real number) that if lim x-> + or - ∞ (infinity) of f(x) = + or - ∞, then lim x-> + or - ∞ of 1/f(x) = 0.

Prove (using the definitions of the limit at infinity and at a real number) that if
lim x-> + or - ∞ (infinity) of f(x) = + or - ∞, then lim x-> + or - ∞ of 1/f(x) = 0.