Let f and g be real functions. If $\mathrm{P}=\{\mathrm{x}: \mathrm{f}(\mathrm{x})=0\}$ and $\mathrm

Question

Let f and g be real functions. If $\mathrm{P}=\{\mathrm{x}: \mathrm{f}(\mathrm{x})=0\}$ and $\mathrm{Q}=\{\mathrm{x}: \mathrm{g}(\mathrm{x})=0\}$ then $\mathrm{P} \cup \mathrm{Q}=$

Professor PC Thomas Classes · Answer

$
\begin{aligned}
P \cup Q= & \{x: f(x)=0 \quad 	ext { or } g(x)=0\} \
& =\{x: f(x) g(x)=0\}
\end{aligned}
$