diff --git a/lib/libc/stdio/getwc.3 b/lib/libc/stdio/getwc.3
index 0ec3d1f0cf0b..7986b01561ca 100644
--- a/lib/libc/stdio/getwc.3
+++ b/lib/libc/stdio/getwc.3
@@ -112,3 +112,10 @@ and
 functions
 conform to
 .St -isoC-99 .
+.Sh HISTORY
+A version of the
+.Fn getc
+and
+.Fn getw
+functions appeared in
+.At v1 .
diff --git a/lib/libc/stdlib/atof.3 b/lib/libc/stdlib/atof.3
index b02cf0277656..47e6c8846a1b 100644
--- a/lib/libc/stdlib/atof.3
+++ b/lib/libc/stdlib/atof.3
@@ -32,7 +32,7 @@
 .\"     @(#)atof.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 4, 1993
+.Dd April 1, 2020
 .Dt ATOF 3
 .Os
 .Sh NAME
@@ -93,3 +93,8 @@ function conforms to
 .St -isoC ,
 and
 .St -isoC-99 .
+.Sh HISTORY
+The
+.Fn atof
+function appeared in
+.At v1 .
diff --git a/lib/libc/stdlib/atoi.3 b/lib/libc/stdlib/atoi.3
index c68a3280f723..628258f50968 100644
--- a/lib/libc/stdlib/atoi.3
+++ b/lib/libc/stdlib/atoi.3
@@ -32,7 +32,7 @@
 .\"     @(#)atoi.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 13, 2018
+.Dd April 1, 2020
 .Dt ATOI 3
 .Os
 .Sh NAME
@@ -85,3 +85,8 @@ function conforms to
 .St -isoC ,
 and
 .St -isoC-99 .
+.Sh HISTORY
+The
+.Fn atoi
+function appeared in
+.At v1 .
diff --git a/lib/msun/man/cos.3 b/lib/msun/man/cos.3
index cca128d1cb60..87a0b6cddc76 100644
--- a/lib/msun/man/cos.3
+++ b/lib/msun/man/cos.3
@@ -28,7 +28,7 @@
 .\"     from: @(#)cos.3	5.1 (Berkeley) 5/2/91
 .\" $FreeBSD$
 .\"
-.Dd January 24, 2008
+.Dd April 1, 2020
 .Dt COS 3
 .Os
 .Sh NAME
@@ -81,3 +81,8 @@ functions return the cosine value.
 .Sh STANDARDS
 These functions conform to
 .St -isoC-99 .
+.Sh HISTORY
+The
+.Fn sin
+function first appeared in
+.At v1 .
diff --git a/lib/msun/man/exp.3 b/lib/msun/man/exp.3
index 213f9141857e..2244bfac375a 100644
--- a/lib/msun/man/exp.3
+++ b/lib/msun/man/exp.3
@@ -28,7 +28,7 @@
 .\"     from: @(#)exp.3	6.12 (Berkeley) 7/31/91
 .\" $FreeBSD$
 .\"
-.Dd December 8, 2017
+.Dd April 1, 2020
 .Dt EXP 3
 .Os
 .Sh NAME
@@ -190,3 +190,8 @@ and infinite x, i.e., independently of x.
 .Sh STANDARDS
 These functions conform to
 .St -isoC-99 .
+.Sh HISTORY
+The
+.Fn exp
+function appeared in
+.At v1 .
diff --git a/lib/msun/man/sin.3 b/lib/msun/man/sin.3
index b5c864a64b2e..36648aebc441 100644
--- a/lib/msun/man/sin.3
+++ b/lib/msun/man/sin.3
@@ -29,7 +29,7 @@
 .\"     from: @(#)sin.3	6.7 (Berkeley) 4/19/91
 .\" $FreeBSD$
 .\"
-.Dd January 24, 2008
+.Dd April 1, 2020
 .Dt SIN 3
 .Os
 .Sh NAME
@@ -80,3 +80,8 @@ functions return the sine value.
 .Sh STANDARDS
 These functions conform to
 .St -isoC-99 .
+.Sh HISTORY
+The
+.Fn sin
+function first appeared in
+.At v1 .