Integrals

What is Integrals?

Integral calculus helps in finding the anti-derivatives of a function. These anti-derivatives are also called the integrals of the function. The process of finding the anti-derivative of a function is called integration. The inverse process of finding derivatives is finding the integrals. The integral of a function represents a family of curves. Finding both derivatives and integrals form the fundamental calculus.

Given a function, \(f\left( x \right)\), an anti-derivative of \(f\left( x \right)\) is any function \(F\left( x \right)\) such that $$F'\left( x \right) = f\left( x \right)$$ If \(F\left( x \right)\) is any anti-derivative of \(f\left( x \right)\) then the most general anti-derivative of \(f\left( x \right)\) is called an indefinite integral and denoted, $$\int{{f\left( x \right),dx}} = F\left( x \right) + c\hspace{0.25in},c{\mbox{ is an arbitrary constant}}$$ In this definition the \(\int{{}}\) is called the integral symbol, \(f\left( x \right)\) is called the integrand, \(x\) is called the integration variable and the "\(c\)" is called the constant of integration.

Example of Integral

$$ \int \sin^3(x) e^{-5x} dx $$


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