Show that \((s – t)^2, (s^2 + t^2)\) and \((s + t)^2\) are in Arithemtic Progression ?
 
Ans:
 
\(a_2 - a_1=\)
 
\(a_3 - a_2=\)
 
\(a_{2} – a_{1}\) \(a_{3} – a_{2}\)
 
Therefore, \((s – t)^2, (s^2 + t^2)\) and \((s + t)^2\)  are
Answer variants:
\(s-t\)
\(2st\)
\(s+t\)
\(st\)