Antiderivative

Antidifferentiation (also called indefinite integration) is the process of finding a certain function in calculus. It is the opposite of differentiation. It is a way of processing a function to give another function (or class of functions) called an antiderivative. Antidifferentiation is like integration—but without limits. This is why it is called indefinite integration. When represented as single letters, antiderivatives often take the form of capital roman letters such as  and .

In general, an antiderivative is written in the form , where:

 The long S, ,  is called an integral sign. In integration, the integral sign has numbers on it. Those numbers tell you how to do the integration. Antiderivatives are different. They do not have numbers on their integral signs.
 is the equation you are integrating.
 The letters  mean "with respect to ". This tells you how to do the antidifferentiation.

 Simple antidifferentiation 

A function of the form  can be integrated (antidifferentiated) as follows:

 Add 1 to the power , so  is now .
 Divide all this by the new power, so it is now .
 Add the constant , so it is now .

This can be shown as:

 (also known as the power rule of integral)

When there are many terms, we can integrate the entire function by integrating its components one by one:

(This only works if the parts are being added or taken away.)

 Examples 

Changing fractions and roots into powers makes it easier:

 Integrating a bracket ("chain rule") 

To integrate a bracket like , a different method is needed. It is called the chain rule. It is like simple integration, but it only works if the  in the bracket is linear (has a power of 1), such as  or —but not  or .

For example,  can be determined in the following steps:

 Add 1 to the power , so that it is now 
 Divide all this by the new power to get 
 Divide all this by the derivative of the bracket  to get 
 Add the constant  to give 

 Examples 

Related pages

 Fundamental theorem of calculus
 Integral
 Numerical integration
 Partial fraction decomposition

 References 

Category:Mathematical analysis
Category:Calculus