what is dx in calculus

In calculus, "dx" represents an infinitesimal change in x. It is used to indicate the variable of integration in indefinite integrals and to specify the variable being integrated over in definite integrals. The "d" in "dx" should remind you of a delta ∆, which is the symbol for change. The dx in integrals is necessary because it tells you which variable to integrate and represents the differential, or the difference between two values of x. It is important to note that dx has no numerical value, but rather captures the idea of taking the limit of smaller and smaller interval sizes to figure out something precisely about a continuous function.