Iterated integral

In calculus an iterated integral is the result of applying integrals to a function of more than one variable (for example ${\displaystyle f(x,y)}$ or ${\displaystyle f(x,y,z)}$) in a way that each of the integrals considers some of the variables as given constants. For example, the function ${\displaystyle f(x,y)}$, if ${\displaystyle y}$ is considered a given parameter, ${\displaystyle f(x,y)}$ can be integrated with respect to ${\displaystyle x}$, ${\displaystyle \int f(x,y)dx}$. The result is a function of ${\displaystyle y}$ and therefore its integral can be considered. If this is done, the result is the iterated integral

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