1.1

Topic

Change in Tandem A function is a mathematical relation that maps a set of input values to a set of output values such that each input value is mapped to exactly one output value. The set of input values is called the domain of the function, and the set of output values is called the range of the function. The variable representing input values is called the independent variable, and the variable representing output values is called the dependent variable. 1.1.A.2 The input and output values of a function vary in tandem according to the function rule, which can be expressed graphically, numerically, analytically, or verbally. 1.1.A.3 A function is increasing over an interval of its domain if, as the input values increase, the output values always increase. That is, for all a and b in the interval, if a < b, then f a( ) < f b( ). 1.1.A.4 A function is decreasing over an interval of its domain if, as the input values increase, the output values always decrease. That is, for all a and b in the interval, if a < b, then f a( ) > f b( ).