3. ---Could
you tell me ____ to have the picnic? ---Near
A. what B. why C. when D. where
2. The victim was killed ____ a gun ____ his wife ____ a cold winter morning.
A. with, by, in B. by, by, on C. with, by, on D. in, by, in
1. ---Have you seen ____ pen? I left
it here just now.
---Is it ____ yellow one? I think I saw it somewhere.
A. a, the B. the, the C. the, a D. a, a
22.
(本題滿分14分)已知數(shù)列
的前
項(xiàng)和為
,對一切正整數(shù)
,點(diǎn)
都在函數(shù)
的圖象上,且過點(diǎn)
的切線的斜率為
.
(1)求數(shù)列
的通項(xiàng)公式;
(2)若
,求數(shù)列
的前
項(xiàng)和
;
(3)設(shè)
,等差數(shù)列
的任一項(xiàng)
,其中
是
中的最小數(shù),
,求
的通項(xiàng)公式.
21. (本題滿分12分)
如圖,過橢圓
的左焦點(diǎn)
作x軸的垂線交橢圓于點(diǎn)P,點(diǎn)A和點(diǎn)B分別為橢圓的右頂點(diǎn)和上頂點(diǎn),OP∥AB.
(1)求橢圓的離心率e;
(2)過右焦點(diǎn)
作一條弦QR,使QR⊥AB.若△
的面積為
,求橢圓的方程.
20. (本題滿分12分)已知函數(shù)
,其中
.
(1)討論函數(shù)f(x)的單調(diào)性;
(2)當(dāng)
時,求函數(shù)f(x)的最大值.
19.
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