math package: minor documentation fix
math package: minor documentation fix

R=rsc
CC=golang-dev
http://codereview.appspot.com/424041

tv42/old-go,nightlyone/golang,tianon/debian-golang,h8liu/golang,nightlyone/golang,ssrl/go,ssrl/go,dsriram/golang,h8liu/golang,pombredanne/go-deleteme,apparentlymart/golang,gnanderson/go,dsriram/golang,tianon/debian-golang,ssrl/go,apparentlymart/golang,h8liu/golang,bdwalton/debian-golang,dsriram/golang,nightlyone/golang,gnanderson/go,tianon/debian-golang,bdwalton/debian-golang,h8liu/golang,nightlyone/golang,ssrl/go,pombredanne/go-deleteme,gnanderson/go,apparentlymart/golang,dsriram/golang,bdwalton/debian-golang,tv42/old-go,tv42/old-go,apparentlymart/golang,tv42/old-go,tv42/old-go,h8liu/golang,tv42/old-go,apparentlymart/golang,nightlyone/golang,pombredanne/go-deleteme,h8liu/golang,bdwalton/debian-golang,dsriram/golang,tianon/debian-golang,bdwalton/debian-golang,pombredanne/go-deleteme,tianon/debian-golang,bdwalton/debian-golang,tianon/debian-golang,ssrl/go,ssrl/go,ssrl/go,dsriram/golang,gnanderson/go,pombredanne/go-deleteme,apparentlymart/golang,h8liu/golang,tianon/debian-golang,dsriram/golang,pombredanne/go-deleteme,nightlyone/golang,tv42/old-go,nightlyone/golang,pombredanne/go-deleteme,gnanderson/go,gnanderson/go,bdwalton/debian-golang,gnanderson/go,apparentlymart/golang,bdwalton/debian-golang,tianon/debian-golang