Using \matbb{Z} and \textregistered in Math Mode

Question

How can you use the two symbols in the Math mode?

My tex

$\matbb{Z}$
$\textregistered$

My formatting code

\documentclass{bmcart}

%%% Load packages
%\usepackage{amsthm,amsmath}
%\RequirePackage{natbib}
%\RequirePackage{hyperref}
\usepackage[utf8]{inputenc} %unicode support
%\usepackage[applemac]{inputenc} %applemac support if unicode package fails
%\usepackage[latin1]{inputenc} %UNIX support if unicode package fails
\usepackage{amsmath, amsfonts, amssymb}
\usepackage[T4, OT1]{fontenc}
\usepackage{newunicodechar}
%\usepackage{unicode-math}
\newunicodechar{ƒ}{{\fontencoding{T4}\selectfont\m f}}
\newunicodechar{Ƒ}{{\fontencoding{T4}\selectfont\m F}}

I get these warnings and errors

LaTeX Warning: Command \textregistered invalid in math mode on input line 248.

LaTeX Warning: Command \textcircled invalid in math mode on input line 248.

(/usr/local/texlive/2013/texmf-dist/tex/latex/base/omscmr.fd)

LaTeX Warning: Command \textcircled invalid in math mode on input line 248.

LaTeX Font Warning: Font shape `OT1/cmss/m/it' in size <8> not available (Font)

l.373 $\matbb {Z}$ [3] Overfull \hbox (4.19527pt too wide) detected at line 404 $\OML/cmm/m/it/10 ^^K < ^^L \OT1/cmr/m/n/10 : \OML/cmm/m/it/10 Q\OT1/cmr/m/n/1 0 (\OML/cmm/m/it/10 ^^Ue[] \OT1/cmr/m/n/10 + \OML/cmm/m/it/10 ^^Ve[]\OT1/cmr/m/ n/10 )(\OML/cmm/m/it/10 x; ^^Q\OT1/cmr/m/n/10 ) = \OMS/cmsy/m/n/10 j\OML/cmm/m/ it/10 ^^U\OMS/cmsy/m/n/10 j[]\OML/cmm/m/it/10 ^^N[]\OT1/cmr/m/n/10 (\OML/cmm/m/ it/10 ^^V\OT1/cmr/m/n/10 ) + \OMS/cmsy/m/n/10 j\OML/cmm/m/it/10 ^^V\OMS/cmsy/m/ n/10 j[]\OML/cmm/m/it/10 ^^N[]\OT1/cmr/m/n/10 (\OML/cmm/m/it/10 ^^V\OT1/cmr/m/n /10 ) + 2\OML/cmm/m/it/10 Re\OT1/cmr/m/n/10 (\OML/cmm/m/it/10 ^^U[]e[]\OT1/cmr/ m/n/10 (\OML/cmm/m/it/10 x\OT1/cmr/m/n/10 ))1[](\OML/cmm/m/it/10 ^^Q\OT1/cmr/m/ n/10 )\OML/cmm/m/it/10 =\OT1/cmr/m/n/10 (\OML/cmm/m/it/10 ^^L \OMS/cmsy/m/n/10 ^^@ \OML/cmm/m/it/10 ^^K\OT1/cmr/m/n/10 )\OML/cmm/m/it/10 :$

LaTeX Warning: Command \m invalid in math mode on input line 413.

and in a separate window:

Answer 1

Use mathbb instead of matbb and try $\text{\textregistered}$ instead of $\textregistered$.

Also, be aware that the basic LaTeX \textregistered command produces a "faked" symbol. To get a better-looking symbol, be sure to load the textcomp package.