WolframAlpha

Online Integral Calculator

Solve integrals with Wolfram|Alpha

More than just an online integral solver

Wolfram|Alpha is a great tool for calculating antiderivatives and definite integrals, double and triple integrals, and improper integrals. The Wolfram|Alpha Integral Calculator also shows plots, alternate forms and other relevant information to enhance your mathematical intuition.

Integral results with plots, alternate forms, series expansions and answers

Learn more about:

Integrals

Tips for entering queries

Use Math Input above or enter your integral calculator queries using plain English. To avoid ambiguous queries, make sure to use parentheses where necessary. Here are some examples illustrating how to ask for an integral using plain English.

View more examples

Access instant learning tools

Get immediate feedback and guidance with step-by-step solutions for integrals and Wolfram Problem Generator

Step-by-step solutions for integrals with detailed breakdowns and unlimited Wolfram Problem Generator eigenvalue practice problems

Learn more about:

What are integrals?

Integration is an important tool in calculus that can give an antiderivative or represent area under a curve.

The indefinite integral of f (x)f x, denoted Start Integral, Start integrand, f (x) , integrand End,Start first variable, x , first variable End , Integral Endf xdx, is defined to be the antiderivative of f (x)f x. In other words, the derivative of Start Integral, Start integrand, f (x) , integrand End,Start first variable, x , first variable End , Integral Endf xdx is f (x)f x. Since the derivative of a constant is 0, indefinite integrals are defined only up to an arbitrary constant. For example, Start Integral, Start integrand, Start Sine, Start angle, x , angle End , Sine End , integrand End,Start first variable, x , first variable End , Integral End = - Start Cosine, Start angle, x , angle End , Cosine End +constantsinxdx = -cosx+constant, since the derivative of − Start Cosine, Start angle, x , angle End , Cosine End + constant−cosx + constant is Start Sine, Start angle, x , angle End , Sine Endsinx. The definite integral of f (x)f x from x = ax = a to x = bx = b, denoted Start Definite Integral, Start first lower limit, a , first lower limit End,Start first upper limit, b , first upper limit End,Start integrand, f (x) , integrand End,Start first variable, x , first variable End , Definite Integral Endbaf xdx, is defined to be the signed area between f (x)f x and the xx axis, from x = ax = a to x = bx = b.

Both types of integrals are tied together by the fundamental theorem of calculus. This states that if f (x)f x is continuous on [a,b]a,b and F(x)Fx is its continuous indefinite integral, then Start Definite Integral, Start first lower limit, a , first lower limit End,Start first upper limit, b , first upper limit End,Start integrand, f (x) , integrand End,Start first variable, x , first variable End , Definite Integral End = F(b) - F(a)baf xdx = Fb - Fa. This means Start Definite Integral, Start first lower limit, 0 , first lower limit End,Start first upper limit, π , first upper limit End,Start integrand, Start Sine, Start angle, x , angle End , Sine End , integrand End,Start first variable, x , first variable End , Definite Integral End = (- Start Cosine, Start angle, π , angle End , Cosine End ) - (- Start Cosine, Start angle, 0 , angle End , Cosine End ) = 2π0sinxdx = -cosπ - -cos0 = 2. Sometimes an approximation to a definite integral is desired. A common way to do so is to place thin rectangles under the curve and add the signed areas together. Wolfram|Alpha can solve a broad range of integrals ..

How Wolfram|Alpha calculates integrals

Wolfram|Alpha computes integrals differently than people. It calls Mathematica's Integrate function, which represents a huge amount of mathematical and computational research. Integrate does not do integrals the way people do. Instead, it uses powerful, general algorithms that often involve very sophisticated math. There are a couple of approaches that it most commonly takes. One involves working out the general form for an integral, then differentiating this form and solving equations to match undetermined symbolic parameters. Even for quite simple integrands, the equations generated in this way can be highly complex and require Mathematica's strong algebraic computation capabilities to solve. Another approach that Mathematica uses in working out integrals is to convert them to generalized hypergeometric functions, then use collections of relations about these highly general mathematical functions.

While these powerful algorithms give Wolfram|Alpha the ability to compute integrals very quickly and handle a wide array of special functions, understanding how a human would integrate is important too. As a result, Wolfram|Alpha also has algorithms to perform integrations step by step. These use completely different integration techniques that mimic the way humans would approach an integral. This includes integration by substitution, integration by parts, trigonometric substitution and integration by partial fractions.