BÀI T P MŨ VÀ LÔGARIT

4 5 5

1

16

2

- 25

log 64 log 0,125 log 1. 2. 3. 4. Bài 1 : TÍNH log 125 1 5

3

3

3 3

0,125

3

9 3

8

7

log 15 8

log 27 log 729 5. 6. 7. 8. log 3 3 log

7

( 3 log 3 3 3

9 3

7

log 5 81

log 81 27

log 4 3

log

64

2 2

log 3 9. 10. 11. 12. log 7 343 2 2 2 )

3 9

)

3 2log 3

+ 3log 3 2log 5

- log 2 2 log

3

10

16

8

2

3

27

13. 14. 16. 2 15. ( æö÷ç ÷ç ÷çè ø æö÷ç ÷ç ÷çè ø 1 3 1 3

1 29

9

log 6 5

log 8 7

log 5 3

log 36 9

9

1 3

19. 17. 18. 20. 10 + 4 4 + 2 log 3

4log 7 3

27

2 log 3

9

125

2

21. 22. 23. 24. + + 25 49+ 81 27

- log 2 log 5 3 + 1 log 4 3

-+ 4

log 5

2

3

5

2

3

5

3

5

4

+

)

( loga a a

) a a 3.

1 a

log 2. 4. 1. Bài 2: TÍNH ( loga a a a a a a 4 a a

a a a log

a Bài 3

a b = . TÍnh 3

a b = . Tính 5

b a

A= log 1. Cho log 2. Cho log b a

ab

= B log b a

a b

a b =

a b =

3

3

2

a = C log 7 13 3. Cho log . TÍnh 4. Cho log . TÍnh b

a

ab log b

15

16

4

5

Bài 4. Tính A = 1.

x =

2009!

3 1 log

2009

o

o

3 ln tan 2 o

4 o ln tan 3 o

log 2.log 3.log 4...log 14.log 15 1 + + = + + ... B 2. v i ớ 1 log x x x log x 1 log o + + ln tan 89

x = theo x , bi 3. 4. 5. t ế

2 o + + ln tan1 ... o ln tan1 .ln tan 2 .ln tan 3 ...ln tan 89 log 16 6 log

= log 27 12 = a lg 3, 30 b theo a và b , bi 6.

125 log 135 3

= lg 2 = b C = D = E = F = G = theo a và b , bi 7. t ế a t ế log 5, 2 log 3 2

)

2

(

)2

( log 3 3

ị + = - - ậ 2 x log 3 x y x x = - y x 2 1. 2. 3. : Tìm t p xác đ nh c a các hàm s Bài 5 ố ( ) = log 2x y 2

1

2

2

(

) - + 3

4

(

) 6

1 3

2

2

= y log x 1 = - - + y 16 x .log x 5 x 4. 5. 6.

( log 9 3

)

2

= + - + - y x 2 x x

2

( log 7 5

)2

3

2

x 3 = - - y x x 7. 8. 9. = y log + + 4 x - x 2

5

1 5

1 1 lg

x

= y log x x æ ç log ç ç ç è ö+ ÷ 1 ÷ ÷ ÷ + 3 ø

1 1 lg

y

1 1 lg

z

-= 10

-= 10

-= 10

ng trình sau:

ươ

2

+

x

x

x log 1

log

log

+ = 2

Bài 6 : Cho và . Ch ng minh : ứ y z x

- - 11.

i các ph Bài 7: Gi ả + + = x x 2 1 1 1. 27 9

x

2

(

) 1

4 6 2.3 0 x = - - + + + = x x log 2 6 35 6 35 12

)

2.

(

x

tan

tan

log 1 2

)

x =

= 1 x ( + + - x + 5 2 6 5 2 6 10

)

3.

12. ( 13. (

(

2

12 .log 2 1 x log 4

x

x

- + 2

2

+

x

2

x

4

4 - =

+ 4. 2 5 3

+= x 3

x 2

2

1

2

3

)

x 3.25

- - + - 14. 2 6 0 - - - - - + - + + =

) ) ) ( 5 2 ( x x 3 10 .5

5.

x 2

x 2

+ - = 2 x 3 0 15. 448

(

(

) = 1 log

6.

2

2

x 2 4 log 2

x

cot

cot

+

1

1

x =

) 3

) 3

7.

x 2.3

x 6.3

x

+ = - - 3 x x 3 log 2 x 6 x log 2 2 - + + - - - 2 2 4 = x 3 9

x =

+ + - + = 2 3 2 3 4

)

)

) + 3 log 2 ( (

x x 8. 27 12

x 2.8

2

16. 17. ( 18. (

x

x

2 1 2sin

2 2cos

1

- - Ø ø + + + = Œ œ 8 3 8 3 6 19.

)

)

x

(

(

9. 2

x

= - 3x º ß

x =

(

) 3

) 3

x 4

10.

= + + - 20. ( 2 2

Bài 8: Gi

2

ng trình sau: =

)

( log

) 10

1.

2

2

(

)

2.

( log log 2 4 ) + 2 log 2

2

+ + = - x x 2 x x log 2 log4 11. 1 2 + + + + x x x = + 7 12 3 log 3 log 2

x log 5 4 1

3.

5

3

x

x

2 +

- - x x log 4 log 8 2 x x log 2 log 8 4 16 i các ph ươ ả ( ) + log log 4 2 ( ( x 3 ) = - x x 12.

) 1

- - 3 log 3 ( = x - = x log 3 1 0 ) ( 3 = 1 7 13.

x

= x +

)

2 log 2 x x 14. 3.25 2.49 ) ( x log log 15. 9 3

x 5.35 ( log log 3 9

3

log 2 = + = + + x 3 log 4 + x 4. 6 8 10 + x x x 5. 3 4 5 = x x 6. 9 12 15

2

) (

) (

) (

x x 7. 12 16

x 20

16

4

+ = x x x log 16. ( log 2 log 4 log 8

) x = ) (

)

( 6 log 2

x

x

- + x x x x - = - 3 2 17. log 5 log 2 2 3 log 5

27

x +

x 3

x 2

9.

81

2

1

(

x 2 1 3

2

5

ươ

(cid:230) (cid:246) (cid:230) (cid:246) (cid:230) (cid:246) = + - - - 18. x 2 6 (cid:231) ‚ (cid:231) ‚ (cid:231) ‚ x x x x = x 575 + 1 log + 1 log Ł ł Ł ł Ł ł 1 = - 6 - - - = 4 3 1 3 -+ x 3 x 3 1 2 ) - + = x 7 2 0 19. -

2006

) + 5 log x 2 ng trình sau: i các ph ) ( = + - x x 5 x 2 3 2 0 2.5

- - - - - + - x x 1 2005 6.

x x 8. 345 460 + 1 log 3 + 1 log 9 ( x log 2 10. 2 Bài 9: Gi x 5 25 1.

2005 = )

3

( log

) + - 1

( log

) = 2 1 log

- 2006 ( x + 2 x x + x x = + 7.

2.

)

)

x

log

log7

1 1 2 + + x x 2log 4 1 4 ( log 3 2 1 ( log 3 6

)2

= = 8.

3.

2 .log 3 1 x

( x log 3 3

25

4.

5 log 5

x

x

3

2

x+ x 98 x 7 log .log = + - x log log6 9. x log 2 125 x 10 + 3

-+ 3 3

- x + 25 = - 10. x 8

) ( = x log 3 1 ( x log 125 5 5. 5 Bài 10*: Gi ả

1.

2

4 +

i ph log 3log 4log 5...log (

)

( n n (

3 log

= - „ log 6 x x log

2.

a

a

a

n

1

+

=

+

3

n

x

log

+ + ...

x

log

x

log

x

log

x ) = ng trình sau: ươ )+ = 1 10 ) ( ) + 2 0

3.

n

n

n

n

2

=

+

2

4.

x

2

x

x

(

)

- - log 2 = 2 1

5.

2

4

log 6 log 64 3 ) x+ 1 1 .log +

( (

)

)

3

x

= 2 ( log log 9 x 3 x 1

6.

x

log 2 3

log 3

x 3 =

7.

6 4

- log x x+ + x ( + x - = x 11 0

8.

3

2 3

+ - log + = 4 x 2 log x 4

9.

2

2

3

3

2

+ + = + + log x x 3log x x

3

) 3 log log 2 3

12) log ( x .log x log x .log 2 log 4 3 = -

10. 11.

1

x x x

)

12.

( log log 3

27

3

27

3

= + x 3 2.2 ) 7. ( x log x log

2

3

3

2

x+

2

+ = log x log x 13.

(

)

log

x

2

log 6 2

2

- - x ) + 2 + ) = 1 6 14. .log x ( x log 2 3 3 3.log ( x + log 2 3 log 2 3

15. + =

2 2

2

x

+ 1

x

- x 6.9 x .log x 13. 1).log 4 0

(

)

19.

5

5

- - 6. x + + = 16. x 2( x 17. (x + 4).9x - (x + 5).3x + 1 = 0 18. 8x - 7.4x + 7.2x + 1 - 8 = 0 ) ( = + x .log 3 log 3 2 4 log 3 5

3

20.

2

x

x

21.

- log x 3.log + = x 2 0

=

(

log 3 ) =

(

) 1

22.

3

+ 2 x

2 2 2 log 3 3 3.log (

2 ) =

23.

2 2

- x+ + x ) 6 2.log ( log 4 x log 2 x 5

2 4 log

24.

3

3

+ = - log 2 x

) 7 1

25.

2

2

2 4 2

2

= - + x ( 2.log x log x

26.

( log 8 2

= + 8 x log

(

) - + = 1

) 1

27.

2

2

2

x

2 log 3 x+ 2 i các ph

- .log x ) ( x 2 3.log + x 2.log x log x .log log

18 ng trình sau

x 2 8 2 2 + x 2 log 28. 2 3 . Gi B aøi 11

ả 1. 3x + 5x = 6x + 2 2. 4x = 3x + 1 x

= ươ

x =

+ + - 3 2 3 4 2

)

)

(

x

x

3. (

2

3

2

x

x

+ x

2

2

2

+

+ 1)

x

(

x

x

x

- - - 2 2 8 2 x x

-+ 1 2 + - 3 x

+ x

x

3 1 +

2

2

x

x

2 +

+ 1 2 + + x - 5.2 2 0

x

+ - - 4. 12.9x - 35.6x + 18.4x = 0 + = 5. 3 6 6. 125x + 50x = 23x + 1 8 = + 7. 8. x2.2x + 4x + 8 = 4.x2 + x.2x + 2x + 1 9. = 4 10. 2. 4 = 2 11. 4x + (x – 8)2x + 12 – 2x = 0 = 2 12. x 12 4 7).2 4 0 x (

(

x

x =

+ + - 13. 12.9x - 35.6x + 18.4x = 0 ) ) 14. ( x x = 3 2 2 3 2 2 6

- 6 + + 2 18 2

2 1

1

x

2

2

+

x x

x

x x

3

2

- 2 - - 15. 2 16. 3x + 33 - x = 12. 17. 2008x + 2006x = 2.2007x += x 18. 5 2 19. + = 2 5 2 x

= 2

x

1

+

y (

2 )

(

)

=

log

x

y

x

log

= y

1

+ x y y 3

2

2

2

3

(cid:236) (cid:236) - (cid:239) (cid:239) 20. 4 = 3 4 ng trình sau: i h ph Bài 12: Gi ả ệ ươ + = + x y y 5 3 2 (cid:237) (cid:237) 1. 5. - - - (cid:239) (cid:239) (cid:238) (cid:238)

2

x y

x

+

= +

(

)

=

x

y

2

2

+ 1 2

5

5

5

) ( log 7 log =

7 +

+ (

1 log 2 )

log

x

log 4

y

y ) = 1

4

log + 3 log

( log 5 1 3log

y

x

2

2

5

2

- (cid:236) (cid:236) (cid:239) (cid:239) (cid:237) (cid:237) 2. 6. - (cid:239) (cid:239) (cid:238) (cid:238)

4

(

) = -

)

x

y

5 log

( + x

y

log

2

=

xy

1

2

2

= -

+

=

1

log

x

log

y

2

2 x log y log

log 4 log3

2

3

x

- (cid:236) (cid:236) (cid:239) (cid:239) - (cid:237) (cid:237) 3. 7. (cid:239) (cid:238) (cid:239) - (cid:238)

=

2

5

4

y

y + 1

x

x

4

2

= +

x log

+ = 20 y + x log

y

1 log 9

=

4

4

4

y

+ + x

2

2

(cid:236) - (cid:236) (cid:239) (cid:237) (cid:237) 4. 8. (cid:238) (cid:239) (cid:238)

x

y

=

+

4

3

)

x

3 + = y

1

log

y

9

( log 9 3

1 x

1 + = 2

1 2

ng trình sau: - (cid:236) i h ph : Gi B aøi 13 ả ệ ươ = y x 2 2 2 8 (cid:236) (cid:239) (cid:239) (cid:237) (cid:237) 1. 7. (cid:239) (cid:238) (cid:239) (cid:238)

x

y

(

)

log

y

x

log

1

+

=

4

3

3

1 = y

4 9

2

2

x

+ = y

3

1 4 +

=

x

y

25

(cid:236) (cid:236) - - - - (cid:239) (cid:239) (cid:237) (cid:237) 2. 8. (cid:239) (cid:239) (cid:238) (cid:238)

2

x

1

= 2

x

y

+

= 3

(

3 )

(

)

- = 2 y )2

log

x

y

x

log

= y

1

x

log

y

3

3

5

- + 1 ( 3log 9 9

3

2

2

2

2

2

(cid:236) (cid:236) - (cid:239) (cid:239) (cid:237) (cid:237) 3. 9. - - - (cid:239) (cid:239) (cid:238) (cid:238)

=

+

+

= +

(

)

)

log

xy

log

x

2

x (

log ) +

y (

log ) (

) =

+

( (

y )

1 log8 ( )

log

x

y

x

log

log

y

0

log

x

y

= y

x

log

log3

log

y

x

y

(cid:236) (cid:236) (cid:239) (cid:239) (cid:237) (cid:237) 4. 10. - - - (cid:239) (cid:239) (cid:238) (cid:238)

=

972

x 3 .2

4 log 4

log 3

= (

) =

=

log

x

y

2

log 3 (

)

(

)

4

x

3

y

3

(

)

xy

log

log 2 3

(cid:236) (cid:236) (cid:239) (cid:239) (cid:237) (cid:237) 5. 11. - (cid:239) (cid:239) (cid:238) (cid:238)

3

(

)

x

+ = y

25

4

= + 2

xy

2

2

log

x

log

= y

2

+

2

2

x

y

3

x

= 3 y

12

(cid:236) (cid:236) (cid:239) (cid:237) (cid:237) 6. 12. - (cid:238) - - (cid:239) (cid:238)

5