can every topic in Calculus I & II be rewritten into a multivariable equivalent?

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An example I was thinking of is area between two curves in Calc I/II.

in Multivariable Calculus this was the equivalent

$$\int_{a}^{b} \int_{f(x)}^{g(x)} dxdy = \int_{a}^{b} (g(x)-f(x)) dx$$

so I got to thinking can this work in other topics? namely the volume topics in Calc I/II: Volumes of revolution, Cross-Section Volume, etc.

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It's difficult to decide what "every topic" entails. However, it's true that the calculus on $\mathbb{R}$ which you studied in the first two courses is a subset of calculus on $\mathbb{R}^n$, which is itself a subset of the large field known as analysis.

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The Fundamental Theorem of Calculus, the most important notion in Calc I/II, certainly has a very nice multivariable equivalent: the Stokes theorem. The FTC gives you the integral of $f$ along an interval in terms of the values of $F$ at the boundary, very much like the vector calc form of Stokes:

$$\iint_\Sigma \nabla \times \mathbf{F} \cdot d\boldsymbol{\Sigma} = \oint_{\partial\Sigma} \mathbf{F} \cdot d\mathbf{r}$$

In its modern version, Stokes' theorem generalizes this to orientable manifolds of say dimension $n$ by looking at the antiderivative at the boundary, which would be $n-1$-dimensional.