Contact us
Choose a category below so we can get back to you as quickly as possible.
第一項是a1,最後一項是a(2n+1) 奇數項有n+1項,和S奇=(n+1)[a1+a(2n+1)]/2=132 偶數項有n項,和S偶=n[a2+a(2n)]/2=129 考慮到a1+a(2n+1)=a2+a(2n),兩式相除,得: (n+1)/n=132/129 解得n=43
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.