What is dx mean in intagral?
that x is the variable that you perform the integral over. Variable of integration.
It comes from the defintion of integral, that you sum over the function value multiplying it with a very very small x-intervall (length multiplied with height). Riemann summary. If we make the intervall infinitesimal (dx), the we have to do, in practice, an infinite amount of summations over these "function value" * "length of intervall"
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