vault backup: 2026-10-02 12:01:43

College/AU 26/MATH 224 (Multivar)/Class 10-2.md

@@ -6,4 +6,9 @@
 	- riemann sums: $$\int_{a}^b f(x) dx = \lim_{ n \to \infty } f(x^*_{k}) \Delta x$$
 - double integral
 	- $f(x,y)$
+	- $$\int \int_{R} f(x,y) dA$$
+	- represents the signed volume between the xy plane and the graph of $z=f(x,y)$ above the region $R$
+	- defining region
+		- $$R=[a,b] \times [c,d]$$
+		- x values are between $a$ and $b$ , y values are between $c$ and $d$
 	-