高一數(shù)學(xué)暑假作業(yè)等差數(shù)列

等差數(shù)列看一看【知識(shí)回憶】1．?dāng)?shù)列：按照一定順序排列著一列數(shù)．2．?dāng)?shù)列分類：遞增數(shù)列、遞減數(shù)列、常數(shù)列、擺動(dòng)數(shù)列3．?dāng)?shù)列遞推公式：表示任一項(xiàng)SKIPIF1<0與它前一項(xiàng)SKIPIF1<0〔或前幾項(xiàng)〕間關(guān)系公式．4．對(duì)任意數(shù)列{}前項(xiàng)和與通項(xiàng)關(guān)系：5．等差數(shù)列定義：如果一個(gè)數(shù)列從第2項(xiàng)起，每一項(xiàng)與它前一項(xiàng)差等于同一個(gè)常數(shù)，那么這個(gè)數(shù)列稱為等差數(shù)列，這個(gè)常數(shù)稱為等差數(shù)列公差．符號(hào)表示:SKIPIF1<0。6．等差中項(xiàng)：由三個(gè)數(shù)SKIPIF1<0，SKIPIF1<0，SKIPIF1<0組成等差數(shù)列可以看成最簡(jiǎn)單等差數(shù)列，那么SKIPIF1<0稱為SKIPIF1<0與SKIPIF1<0等差中項(xiàng)．假設(shè)SKIPIF1<0，那么稱SKIPIF1<0為SKIPIF1<0與SKIPIF1<0等差中項(xiàng)．7．等差數(shù)列通項(xiàng)公式：假設(shè)等差數(shù)列SKIPIF1<0首項(xiàng)是SKIPIF1<0，公差是SKIPIF1<0，那么SKIPIF1<0．8．等差數(shù)列性質(zhì)：假設(shè)SKIPIF1<0是等差數(shù)列，且SKIPIF1<0〔SKIPIF1<0、SKIPIF1<0、SKIPIF1<0、SKIPIF1<0〕，那么SKIPIF1<0；假設(shè)SKIPIF1<0是等差數(shù)列，且SKIPIF1<0〔SKIPIF1<0、SKIPIF1<0、SKIPIF1<0〕，那么SKIPIF1<0．9．等差數(shù)列前SKIPIF1<0項(xiàng)和公式：=1\*GB3①SKIPIF1<0；=2\*GB3②SKIPIF1<0．想一想如何判定數(shù)列是不是等差數(shù)列？練一練1．在等差數(shù)列SKIPIF1<0中，SKIPIF1<0，SKIPIF1<0，那么公差SKIPIF1<0等于〔〕A．B．0C．D．2．在等差數(shù)列SKIPIF1<0中，SKIPIF1<0那么該數(shù)列前SKIPIF1<0項(xiàng)和是〔〕A．SKIPIF1<0B．SKIPIF1<0C．SKIPIF1<0D．SKIPIF1<03．Sn是等差數(shù)列{an}前n項(xiàng)和，假設(shè)SKIPIF1<0QUOTEQUOTE，那么SKIPIF1<0QUOTEQUOTE=〔〕A．3B．5C．D．4．等差數(shù)列SKIPIF1<0前SKIPIF1<0項(xiàng)和為SKIPIF1<0，且滿足SKIPIF1<0，那么數(shù)列SKIPIF1<0公差是〔〕A．SKIPIF1<0B．SKIPIF1<0C．SKIPIF1<0D．SKIPIF1<05．?dāng)?shù)列SKIPIF1<0中，SKIPIF1<0，SKIPIF1<0，假設(shè)SKIPIF1<0是等差數(shù)列，那么SKIPIF1<0等于〔〕A．SKIPIF1<0B．SKIPIF1<0C．SKIPIF1<0D．SKIPIF1<06．等差數(shù)列SKIPIF1<0前SKIPIF1<0項(xiàng)和為SKIPIF1<0，且滿足SKIPIF1<0,SKIPIF1<0，那么使SKIPIF1<0取最大值時(shí)SKIPIF1<0值為A．8B．10C．9或10D．8或97．如果在等差數(shù)列SKIPIF1<0中，SKIPIF1<0，那么SKIPIF1<0．8．在等差數(shù)列中，，那么．9．等差數(shù)列前項(xiàng)和為，假設(shè)，SKIPIF1<0，那么公差等于．10．等差數(shù)列SKIPIF1<0前SKIPIF1<0項(xiàng)和為SKIPIF1<0，且SKIPIF1<0，SKIPIF1<0．〔1〕求數(shù)列SKIPIF1<0通項(xiàng)公式；〔2〕設(shè)SKIPIF1<0，求數(shù)列SKIPIF1<0中最小項(xiàng)．11．設(shè)SKIPIF1<0為等差數(shù)列SKIPIF1<0前SKIPIF1<0項(xiàng)和，且SKIPIF1<0．〔1〕求公差SKIPIF1<0值；〔2〕SKIPIF1<0，求所有滿足條件SKIPIF1<0值．12．等差數(shù)列中，．〔1〕求數(shù)列通項(xiàng)公式及前項(xiàng)和表達(dá)式；〔2〕記數(shù)列前項(xiàng)和為，求值．【等差數(shù)列】等差數(shù)列①anan1d(n2,d為常數(shù))②2anan1an1(n2)③anknb(n,k為常數(shù)1．A【解析】2a13d5，因?yàn)閍14，代入d1an，應(yīng)選試題分析：a2a3A.考點(diǎn)：等差數(shù)列2．B【解析】試題分析：由3a3a52a7a10a1324,有6a46a10a4a104,所以該數(shù)列前13項(xiàng)和13(a4a10)13426,應(yīng)選B.22考點(diǎn)：1.等差數(shù)列性質(zhì)；2.等差數(shù)列前n項(xiàng)和公式.3．A【解析】試題分析：由題意得，設(shè)等差數(shù)列an公差為d，由a39a1，那么a12d9a1d4a1，所以S55a110d45a13，應(yīng)選A．S33a13d15a1考點(diǎn)：等差數(shù)列通項(xiàng)及前n項(xiàng)和公式應(yīng)用．4．D【解析】an)ann(a1Sna13S212，試題分析：因?yàn)镾n，所以，由2S3a1a32n2S3S2a1a2a3a2得2，得2，即aa4，所以數(shù)32222