\[y = x²\]
\[x \in \lbrack - 2;6\rbrack:\]
\[x = - 2 \Longrightarrow y = ( - 2)^{2} = 4;\]
\[x = 0 \Longrightarrow y = 0;\]
\[x = 6 \Longrightarrow y = 6^{2} = 36.\]
\[y \in \lbrack 0;36\rbrack.\]