From f7903bdddb48a163a6902e832247d0f97a8ad664 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sesse@debian.org>
Date: Sun, 2 Dec 2007 15:44:07 +0100
Subject: [PATCH] =?utf8?q?Optimize=20the=20sech=C2=B2(x)=20function=20a=20?=
 =?utf8?q?bit.?=
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---
 foosrank.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/foosrank.cpp b/foosrank.cpp
index 67aee58..d295c21 100644
--- a/foosrank.cpp
+++ b/foosrank.cpp
@@ -32,8 +32,8 @@ static double fac(int x);
 // sech²(x)
 static double sech2(double x)
 {
-	double c = cosh(x);
-	return 1.0 / (c*c);
+	double e = exp(2.0 * x);
+	return 4.0 * e / ((e+1.0) * (e+1.0));
 }
 #endif
 
-- 
2.39.2