Continuity The set on which a function f is defined is called the domain off & it is denoted by dam (f). We will be concerned with functions f such that dam (f) IR & such that f is a real valued function i.e. f(x) EIR VxEdom(f) The symbol f represents the function while f(x) represents the value of the function at x. When a function is given by specifying its values f without mentioning its domain then the domain is understood to be the natural domain i.e. the largest subset of IR on which the function is a well defined real valued function e.g. 1) f(x) = 1 then dam(f) = { XEIR | x=0} is natural domain of f 2) g(x)=1-x then dom (2) = [1,1] is natural domain of h(x)= 4> 1 sinx ... g then dom (h) = {x=R | x= n, ne z} is natural domain of h f(x)=1+x+x then dom (f) = IR is natural domain of f 5) g(x) = log x then dom(g) = (0,00) is natural domain of g