【新高考数学】小题压轴题专练7 基本不等式

小题压轴题专练7基本不等式一、单选题x

11xx

xy()A2B

1C32

D4

11xx

33x

112y(4[(3x)]22

31[(3y)22x2

1x)x31[4]2x

332x

33

13y23

y

x2

x311x2322x2

3x22x3Ca

a

1

()A1B

65

C

22

DbR

ab

ab

(a

abab)

ab)(

tab)4abt(tt(s4)t

42

tt

s)

ss

s

32sss42t2

4328

2b2

y满xy

xyxy

)A

B

C

D

yxxyx(s(tttxytstst

1616ststtt

14164()(4()7st7tt

164151t7

s4tstsB

nmnmmnm2

mn(m

)A

176

B

145

C

D

83m2mn(

(2)

mn(m(n1mmmn

11(n2))5

nm()m

nm1m1214()mn5mn55

1n2

1n

nBcaba

52()A

B

C

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c)

444415[()b

][2

b15)])b]15

|a|

a2

bb615abc5111()(b2b

Ca

22(

)A2B4CD16

y(xx

y(x[xyxy)xy

((2)

2

(22)xy

2

2

xy

xy

16Dl2xyP(l()

1242b

A

720

B

720

C

7620

D

7620l

2xyP(,b)l

2ba4a(3b5)

26a2bb16b)(9)]()119b

1b6(11b)7)20bb20

6(11)

15476ba64Cxyyx

1|(2|x|y

)A

B

C

D

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1|2|y2x

xx24115)44x42

3②x

1|x|1)2|y2xy

1213))22

acabb()

c

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9

b

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ab

b)

b

b

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C

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bb

ab

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22

2(b

2b

bbbDab

2

(

)A

322

B

322

C

322

D

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2b2bb2b

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32

4aa2

2

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ab

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ffaf2fa2f(42)

2

2)

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xy

4y

424(y)xy)xy

22ty

tt

t0t，t09y9Bmn(0,)

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2mnnnm2(4nf)(n(nf

n(

nn2)(n((n

f0n2mf()mC14bax

0R

12(11

)A

1023

B

43

C

D4

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xRab04abb

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a4aB152a

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()A4

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C

D

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cab

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44(a)ab()caba()D16bcba()A

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b

acos

22

r

2rab

2sin

r(

rsin(33A17ac

abc()Aa

b

B

Ca

DA

b

a

b

ab()aab()abcABab

2c

44aa[3]2ab2ab

a

a

2

)

2.54.0625C

22CD2aDABC182

(

)A7B8CD10

ba

9(2a)a)3aaaa3aaa

332

a

2ab22

2

2

b

2

3aab

2

3

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2

8

1a

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BDa

(b)

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(b2(1)()2(1)(b)

)

(

a，b2

)

2

1

2

(1)

2

3a

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()A

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1

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(a)

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14

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2b))abaabbbb

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ab2DAD21

aab

a

2

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a)ab(

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)a(a)

a

a3()

()

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c

bc3c

bca

a

abcaa

tba

3

ta)

a392()tatt

tt

t

3b

a39bcabba

b

f(x)

3xx3(x2)xxx

a3

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4b

2bab0)a0012b2a3b6)4y

bab(a9)(b4)4ab)

ab)24(18)288

tab1218ab

t

tt288

t18)

(t

12(288t288)

t2t122)t2y

t

tt288

[122t

22

yty1

65

22

24

ba

2

2

[13]

13a31ab3133b

3113

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1

2baabf

ab

a3faa2

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bfab3)

3

32

b

f

(3)

b

2)3)

2(33)3

f(3)b21ba3gb0f

2

2

2

2

[3]

tt3]25y

62xyx

y

2xyxyxyxyyxyy

xx3))yyxxy()yxx

t

xyy

t2

28