A function y=f(x) is a rule for determining y when we're given a value of x. Functions can be defined in various ways: by an algebraic formula or several algebraic formulas, by a graph, or by an ex...A function y=f(x) is a rule for determining y when we're given a value of x. Functions can be defined in various ways: by an algebraic formula or several algebraic formulas, by a graph, or by an experimentally determined table of values. (In the latter case, the table gives a bunch of points in the plane, which we might then interpolate with a smooth curve, if that makes sense.)
