Integrand
The quantity being integrated, also called the integral kernel. For example, in intf(x)dx, f(x) is the integrand.
See also
Integral, IntegrationExplore with Wolfram|Alpha
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Cite this as:
Weisstein, Eric W. "Integrand." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Integrand.html