In college mathematics exercises often depend on functions of a real variable.

Methods with only real variables were supposed to be inadequate.

In this case, the function f has to be a function of one real variable.

Thus the only real variable is the frequency of the power supply.

Money is therefore neutral in the sense that it cannot affect these real variables.

Even more generally, we could consider a function of two real variables.

Changes in the money supply could have effects on real variables like output.

A can be regarded as a function of a real variable.

Suppose that f is a function of n 1 real variables.

Each realization is considered as a possible scenario of what the real variable could be.