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- Feb 14, 2012
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Let $a_1,a_2,\,\cdots,\,a_{2n}$ be an arithmetic progression of positive real numbers with common difference $d$. Let
(1) $a_1^2+a_3^2+\cdots+a_{2n-1}^2=x$
(2) $a_2^2+a_4^2+\cdots+a_{2n}^2=y$
(3) $a_n+a_{n+1}=z$
Express $d$ in terms of $x,\,y,\,z,\,n$.
(1) $a_1^2+a_3^2+\cdots+a_{2n-1}^2=x$
(2) $a_2^2+a_4^2+\cdots+a_{2n}^2=y$
(3) $a_n+a_{n+1}=z$
Express $d$ in terms of $x,\,y,\,z,\,n$.