\[y² - 13y - 11 = 0\]
\[D = b^{2} - 4ac =\]
\[= 169 - 4 \cdot ( - 11) \cdot 1 =\]
\[= 169 + 44 > 0\]
\[y_{1} \cdot y_{2} = - 11 \Longrightarrow корни\ разных\ \]
\[знаков.\]