diff --git a/College/AU 26/MATH 224 (Multivar)/Class 10-2.md b/College/AU 26/MATH 224 (Multivar)/Class 10-2.md
index 2efe3fa..1d64e29 100644
--- a/College/AU 26/MATH 224 (Multivar)/Class 10-2.md	
+++ b/College/AU 26/MATH 224 (Multivar)/Class 10-2.md	
@@ -3,4 +3,7 @@
 - definite integral represents the signed area between a function and the x axis between the two bounds
 	- $\int_{a}^b f(x) dx$
 	- for functions with one variable
-- 
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+	- riemann sums: $$\int_{a}^b f(x) dx = \lim_{ n \to \infty } f(x^*_{k}) \Delta x$$
+- double integral
+	- $f(x,y)$
+	- 
\ No newline at end of file