当前位置:首页 > 江苏省南京市金陵中学2018-2019学年高二下学期期末考试数学试题Word版含答案
y0?y0?7?23x07?23x014y0??7k1, 所以k2?2x83?7x083?7x00?7?23x07?23x0即存在m?7,使得k2?7k1.
*19.(1)证明:因为?n?N,都有an?1?(p?1)Sn?2,
an?2?(p?1)Sn?1?2
所以两式相减得an?2?an?1?(p?1)an?1, 即an?2?pan?1,
当n?1时a2?(p?1)a1?2?pa1,
*所以an?1?pan,(n?N),
又因为p?1,所以
an?1an?n, n?1pp所以数列{anana12??,an?2pn?1, }是常数列, nnpppp所以{an}是以2为首项, p为公比的等比数列.
n?1(2)由(1)得an?2p.
1bn?log2(a1a2n所以b2018?2.
n(n?1)11n(n?1)nan)?log2(2p2)?(n?)
nn2017n?1(3)由(1)得an?2p.
1bn?log2(a1a2n因为bn?n(n?1)n(n?1)11n?1. an)?log2(2np2)?log2(2n22k?1)?1?nn2k?132n?2k?3?, 22(2k?1)所以当1?n?k?1时, cn?3?bn, 2当n?k?2时,cn?bn?3. 2因此数列{cn}的前2(2k?1)项的和T2k?2
??(b1?b2??bk?1)?(bk?2?bk?2??b2k?2)
0?1??k(k?1)?(k?2)??2k+1 ?2k?12k?1k(k?1)(k?1)(k?2k?2)(k?1)222. ????2k?12k?12k?1220. (1)设直线y?x与函数f(x)?c1nx相切于点P(x0,c1nx0),
e??函数f(x)?c1nx在点P(x0,c1nx0)处的切线方程为: y?c1nx0?把x?0,y?0代入上式得x0?e,c?2. 所以,实数c的值为2. (2)①由(1)知h(x)?ax?cc2(x?x0),?, x0x0ea?21nx, x设函数h(x)在区间(,e)内有两个极值点x1,x2(x1?x2),
1eaa2ax2?2x?a?0, 令h?(x)?a??2??2xxxx2则ax?2x?a?0,设m(x)?ax?2x?a,
2???0,?22e?因为x1x2?1,故只需??0,,所以, 2?a?1.
e?1?a??m(e)?0,②因为x1x2?1,所以,
M?f(x1)?f(x2)?ax1?aa?21nx1?(ax2??21nx2) x1x2?ax1?aa1?21nx1?(?ax1?21n) x1x1x12a?21nx12 x1?2ax1?2由ax1?2x1?a?0,得a?2x11,且?x1?1. x12?1e2x1x12?1122x1x12?12?21nx1?4(2?1nx1). M?22x1?x1?12x1?1x122设x1?t,
1t?11,令?t?1?(t)?4(?1nt),
e2t+1221?2(t?1)2??(t)?4(?)??0, 22(t+1)2tt(t?1)11上单调递减,从而,1)?(1)??(t)??(), e2e28所以,实数M的取值范围是(0,2).
e?1?(t)(在(高二数学Ⅱ(附加题)
21. 解(1)由题知MN???2 ?1??1 1??0 3??0 3?,所以?det(MN)???2 ?1??7 ?2??7 ?2???2l,
1 3?????????21? ??217?1根据逆矩阵公式,得(MN)???.
?1 0????3?(2)设由L上的任意一点P?(x?,y?)在T作用下得到L?上对应点p(x,y).
3x+y??x???2 ?1??x???x??2x??y??x,?7由?,即解得, ???????????2y?x?1 3??y??y??x?3y?y'?y'??7?因为2x??y??1?0,所以2?即5x?4y?7?0.
即直线L的方程为5x?4y?7?0.
3x?y2y?x??1?0, 77?x2?x?3cos?,?y2?1, 22.解(1)由?得C:3??y?sin?,由pcos?(???4)?22,得pcos??psin??4,即l:x?y?4?0.
x2?y2?1上任取一点P(3cos?,sin?)(0???2?), (2)在C:3则点P到直线l的距离为d?|3cos??sin??4|2|2sin(????3)?4|,0???2?,
2当sin(???3)??1,即??7?时,dmax?32. 623. 解(1)设事件A:“恰用完3次投篮机会”,则其对立事件A:“前两次投篮均不中”, 依题意, P(A)?1?P(A)?1?(1?p)?解得p?221, 253. 5(2)依题意, X的所有可能值为0,1,2,3, 且P(X?0)?(1?p)?24, 2524, 125P(X?1)?p(1?p)2?(1?p)p(1?p)?P(X?3)?p3?27, 12554. 125故P(X?2)?1?P(X?0)?P(X?1)?P(X?3)?X的概率分布列为:
数学期望E(X)?245427213. ?2??3??12512512512524.解(1)如图,以D为坐标原点,分别以直线DA,DC,DD1所在直线为x轴, y轴, z轴,建立空间直角坐标系D?xyz,
AE?(0,2,a), 易得A1B?(0,2,?3),设BE?a,则
因为A1B?AE,所以AB1?AE?(0,2,?3)? (0,2,a)?4?3a?0, 解得a?44,即AE?(0,2,), 33又D1B?(2,2,?3),AC?(?2,2,0),
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