From d3f7d656b02cfbfed33e5495ded617308278eba7 Mon Sep 17 00:00:00 2001
From: handsomezhuzhu <2658601135@qq.com>
Date: Mon, 5 Jan 2026 19:09:43 +0800
Subject: [PATCH] =?UTF-8?q?=E5=85=AC=E5=BC=8F=E4=BF=AE=E6=AD=A3?=
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---
 docs/sop/notes/probability-statistics-notes.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/sop/notes/probability-statistics-notes.md b/docs/sop/notes/probability-statistics-notes.md
index 7304920..c1ffa17 100644
--- a/docs/sop/notes/probability-statistics-notes.md
+++ b/docs/sop/notes/probability-statistics-notes.md
@@ -578,7 +578,7 @@ $$f_{XY}(z) = \int_{-\infty}^{\infty} \frac{1}{|x|}f(x, \frac{z}{x})dx$$
 若X和Y相互独立，边缘概率密度为$f_X(x), f_Y(y)$，则有：
 $$f_{Y/X}(z) = \int_{-\infty}^{\infty} |x|f_X(x)f_Y(xz)dx$$
 
-$$f_{XY}(z) = \int_{-\infty}^{\infty} \frac{1}{|x|f_X(x)f_Y(\frac{z}{x})dx$$
+$$f_{XY}(z) = \int_{-\infty}^{\infty} \frac{1}{|x|}f_X(x)f_Y\left(\frac{z}{x}\right)dx$$
 
 #### (3) M = max{X,Y} 及 N = min{X,Y} 的分布