From c7901188d41f3bd1c34dab5e5139cd8677d374d1 Mon Sep 17 00:00:00 2001 From: Zheyuan Wu <60459821+Trance-0@users.noreply.github.com> Date: Wed, 16 Apr 2025 10:31:20 -0500 Subject: [PATCH] fix jenkinfile errors --- Jenkinsfile | 2 -- pages/Math4121/Math4121_L35.md | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/Jenkinsfile b/Jenkinsfile index 04f7cfe..715851b 100644 --- a/Jenkinsfile +++ b/Jenkinsfile @@ -40,5 +40,3 @@ pipeline { } } } - -} diff --git a/pages/Math4121/Math4121_L35.md b/pages/Math4121/Math4121_L35.md index 08a6fd6..5ba91e9 100644 --- a/pages/Math4121/Math4121_L35.md +++ b/pages/Math4121/Math4121_L35.md @@ -31,3 +31,35 @@ $$ We allow for $A-\infty = -\infty$ and $A+\infty = \infty$ for any $A\in \mathbb{R}$. But not $\infty-\infty$. +#### Immediate Properties of Lebesgue Integral + +If $f$ is measurable and $m(E)=0$, then $\int_E f \, dm = 0$. + +If $E=E_1\cup E_2$ and $E_1\cap E_2=\emptyset$, then $\int_E f \, dm = \int_{E_1} f \, dm + \int_{E_2} f \, dm$. + +#### Corollary + +If $f\leq g$ almost everywhere, ($f\leq g$ except for a set of measure 0), then $\int_E f \, dm \leq \int_E g \, dm$. + +Proof: + +Let $F=\{x\in E: f(x)>g(x)\}$. Then $m(F)=0$. + +$$ +\begin{aligned} +\int_E f \, dm &= \int_{E\setminus F} f \, dm + \int_F f \, dm\\ +&\leq \int_{E\setminus F} g \, dm +\end{aligned} +$$ + + + + + + + +QED + + + +