1.1 function a function is a rule that maps a number to another unique number. the inpu to the function is called the independent variable, and is also called t

1.1 FUNCTION A function is a rule that maps a number to another unique number. The inpu to the function is called the independent variable, and is also called the argument of function. The'outpup or thne Tunction is called the dependent variable. Definition If X and Y two non-empty sets then a relation defined from X to Y is said to be a function if every olement of is assciated witn some unique element of set Y Se f f X a Non-ewp b- 2 X to helbo b >3 2 C C 3 () Domain, Co-domain & Range If y = f(x) is a function such that f is defined from X Y then (1) Domain Set X is called domain of f(x) and it is the set from which the independent variable 'x takes, its values. The independent variables x must be able to take each and every element of set X. fnput (2) Co-domain Set Y is called co-domain of f(x) and it is the set from which the dependent variable y takes its values the dependent variables y cannot take its values outside the co-domain. Oudput (3) Range The set of values that y actually takes for different values of x is called range of f(x) Range is a subset of Y Range co-domain Conmo D-st