Integral Symbol: With Explanations

December 12, 2024
The integral symbol, ∫, is a mathematical symbol for integration published in 1655 by Isaac Newton. It was the first symbol for integration that was both conceived specifically for this purpose and had a specialized notational system.

Isaac Newton was one of the most influential and well-known scientists in modern history. In fact, he can be considered a giant in the area of science. 

Symbol Name
integral
double integral
closed contour / line integral
closed volume integral
closed surface integral
triple integral

He is often attributed with discoveries and innovations in many fields of study since his time at Cambridge; his work enlivened each branch of natural philosophy, from telescopic astronomy to physics, and even alchemy. There are many ways to represent a function by a graph. 

The vertical and horizontal axes of a graph are usually called the x-axis and y-axis respectively. 

Although most graphs have no axes, they may contain lines or other marks indicating specific values of a function. As we all know, integral is a part of advanced math not taught in most schools or colleges. 

Some call it calculus knowledge level, but whatever and wherever, an integral can be clearly defined as a part of limits that is looked upon as an introduction to calculus.

In 1675, Leibniz first introduced the symbol in his private writings. It appeared publicly in 1686 when he published a paper on a “hidden geometry.” It was based on the long s character, and Leibniz thought of an integral as an infinite sum of infinitesimal terms.

The symbol was based on the long s character, which was chosen because Leibniz thought of the integral as an infinite sum of infinitesimal elements The symbol and concept were based on the long s (ſ) character, which Leibniz thought of as an infinite sum of infinitesimal summands.

Double Integral

Double Integrals. Imagine a circle the size of the Earth, and then imagine another one. That's an example of a double integral. 

A Quick search through Google for double integral will tell you that they are the most widely-used part of mathematics that nobody understands. 

The topic of double integral has baffled even some of the best mathematicians in history, including the likes of Gauss and Riemann with their tensor theory, and Fourier, Lagrange, Poincare and Weierstrass who all had theories on how to handle these integrals.

Triple Integral

In mathematical analysis, a triple integral is a three-dimensional generalization of the concept of double integral and is defined as a definite integral with respect to three mutually dependent variables. 

If the domain of integration is an n-dimensional differentiable manifold, then the triple integral evaluates a function of three variables on that manifold.

Line Integral

The line integral is a generalization of the idea of integration. It allows us to find the function that has been used to obtain a given expression, from which the original expression was derived. 

For example, if we consider a volume under the surface \(f(x, y)\), then the line integral gives us the same value as obtained when integrating this function with respect to \(x\), but without integrating with respect to \(y\).

Closed Surface Integral

The closed surface integral is the most useful process to evaluate the integral for a quadric surface. 

This method allows us to compute integrals over closed shapes and obtain results that are often unobtainable in another way. 

However, in this work we will use a different strategy, based on the concept of relative position of points in 4-dimensions, instead of taking all the points that are fixed in space.

In differential topology, a branch of mathematics, the closed surface integral of a function is a way to define a uniquely defined differential form on every compact (dense) closed surface in R^3. 

It is closely related to the surface integrals where the integral is performed over a simplex in R^4 or some other simplex in R^3.

Closed Volume Integral

A closed volume integral is an integral whose independent variable does not vary with respect to the dependent variable . 

For example, if we have a closed volume """V""" and a function f that describes the surface bounding it, then integration of the function f across this closed surface """S""" will yield the constant value of the function f along all of the curve made by tracing ""S"" in space. 

If you want to see all math symbols here is the page you should check.

Related: Greek Letters & Symbols, Math Symbols

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