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In the previous Newton-Raphson example we got the value of the
function and its derivative through separate subprogram calls. Each
function subprogram had a single input argument, namely `x`

and a
single output value, which was passed back to the calling program as
the function return value. It is frequently convenient to have
several input and output values. To illustrate let's see how to
rewrite the Newton-Raphson subprograms so a single call does double
duty by returning the value of the function and its derivative. This
objective takes us into the realm of pointers and references, which we
discuss in more detail in the next lesson. Here we introduce the
terminology and the pattern, first, using pointers and second, using
references.

**Subsections**

Carleton DeTar
2009-09-23