\[\begin{array}{l}
1,\,\,a,\,\,b\,\,\,la\,\,CSC\,\,\, \Rightarrow 2a = 1 + b\\
1,\,\,{a^2},\,\,{b^2}\,\,la\,\,\,CSN \Rightarrow {a^4} = 1.{b^2}\\
\Leftrightarrow \left[ \begin{array}{l}
b = {a^2}\\
b = - {a^2}
\end{array} \right..\\
\Rightarrow TH1:\,\,\,b = {a^2} \Rightarrow 2a = 1 + {a^2}\\
\Leftrightarrow {a^2} - 2a + 1 = 0\\
\Leftrightarrow {\left( {a - 1} \right)^2} = 0\\
\Leftrightarrow a = 1.\\
\Rightarrow b = 1\,\,vo\,\,ly.\\
TH2:\,\,\,b = - {a^2}\\
\Rightarrow 2a = 1 - {a^2}\\
\Leftrightarrow {a^2} + 2a - 1 = 0\\
\Leftrightarrow \left[ \begin{array}{l}
a = - 1 + \sqrt 2 \Rightarrow b = 3 - 2\sqrt 2 \\
a = - 1 - \sqrt 2 \Rightarrow b = 3 + 2\sqrt 2
\end{array} \right..
\end{array}\]
