In scientific researches in the domain of physics we often meet with the
following problem: Being given any function whatever, y = f(x), to find
a curve whose equation shall be

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y = | f(x)dx + C.
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[TEX: y = \int f(x) dx + C.]

Let us take an example that touches us more closely; let us suppose that
we know an induced current, and that we can represent it by a curve
y=f(x). The question is to find the inductive current, that is to say,
the curve represented by the equation

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y = | f(x)dx + C.
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_/

[TEX: y = \int f(x) dx + C.]

The apparatus called an integraph, constructed by Messrs. Napoli and