\title{Mixed multiplication}
\language{en}
\range{-0.9..0.9}
\author{Gang XIAO}
\email{xiao@unice.fr}
\computeanswer{yes}
\format{html}
\precision{10000}

\text{yes=Yes}
\text{no=No}
\text{mt=x,(x+2),(x^2+2),x^2,(x^2-2),
	(x^3+2),exp(x),sin(x),cos(x),(sin(x)+2),
	(sin(x)-2),(cos(x)+2),(cos(x)-2)
}
\text{gd=\no,\no,\yes,\no,\no,
	\no,\yes,\no,\no,\yes,
	\yes,\yes,\yes
}
\integer{N=items(\mt)}
\integer{n=random(1..\N)}
\text{mult=item(\n,\mt)}
\text{bad=\yes,\no}
\text{good=item(\n,\gd)}

\statement{Let \(f: \RR\to \RR) be a real function, Is the following
statement true?
<p><center>
 If \(\mult*f(x)) is continuous, then \(f(x)) is continuous.
</center></p>}

\choice{}{\good}{\bad}

\hint{If h(x)=f(x)g(x), then f(x)=h(x)/g(x) once g(x) is non-zero.}

