Vòng lặp While Do

[r]

A.Mét sè bµi to¸n c¬ b¶n:

1).Gi¶i c¸c ph¬ng tr×nh :

a)

2

2 4x x 256 b) 2 5x x 0 01, c) 2x 3x 216 d)

2 1

4 9 3 2

x



2).Gi¶i c¸c bÊt ph¬ng tr×nh

a) 3x+2 < 9 b)

2 2

2 8 20

1

8 2

x  x



3) Gi¶i c¸c ph¬ng tr×nh :

a) 4x + 2x+1 - 3 = 0 b) 4x +5x = 9x

c) 3x = 11- x d) 4.9x +12x -3.16x = 0

e) 9x +2(x-2).3x +2x -5 = 0

4) Gi¶i c¸c ph¬ng tr×nh :

a) Ln x +ln(x+1) = 0 b) lnx(x+1) =0

c) -log3x +2log2x = 2- logx d) logx +logx2 = log9x

e) log(x2-x-6)+x = log(x+2) +4 e) log(1+ x) = log

3x

B.Mét sè bµi thi tõ n¨m 2002-2008

I.Gi¶i ph ¬ng tr×nh mò vµ logarit

1).23x+1 -7.22x +7.2x -2 = 0 2)3.8x +4.12x -18x -2.27x = 0

3) 9x2

+x − 1 −10 3 x2

+x −2

2x x  4.2x x  2 x 4 0.

5)log3(x-1)2 +log (23 x 1)

= 2 6)logx2 +2log2x4 = log 2x8

7)

x − 1¿3=0 log√2√x +1− log1

2

(3 − x )− log8¿ 8)log2(4x+15.2x +27 ) + 2

1

4.2x 3



9)log4 (x-1) +

1 log2 x+14=

1

2+log2√x+2

. 10)( 2-log3x)log9x3 - 3

4

1

11)log3(3x-1)log3(3x+1-3) = 6 12)

log x (2x  x 1) log (2 x x 1) 4

13)log2(4x+15.2x +27 ) + 2

1

4.2x 3

 14)2(log2x+1)log4x +log2

1

4 = 0.

15)

log x (2x  x 1) log (2 x x1) 4

16).3x- log68x = log6(33x + x2 – 9) 17)log2x + 2log7x = 2 + log2xlog7x 18)logx2(2 + x) + log ❑√2 +x x = 2

II.Gi¶i bÊt ph ¬ng tr×nh vµ logarit

1)

2 0,7 6

4

x





2 1 2

0

x



3)(logx8+log4x2)log2 2x 0. 4) log1

2

√2 x2− 3 x +1+1

2log2( x −1)2≥1

5)logx+1(-2x) > 2 6)log5(4x +144) -4log52 < 1 + log5(2x-2 + 1)

7)

x +1¿3

¿

x+1¿2− log3¿

log3¿

¿

2 1 2

0

x



9)

3

2log (4x 3) log (2 x3) 2

10)(x + 1)

log1

2

2

x + ( 2x + 5)

log1

2 x + 6 0

11)

3 1

3 3

2 2 3

1

3

log  log x log x



 

 

2 0,7 6

4

x





13)2log3(x – 2) + log3(x – 4)2 = 0 14) log22x+(x − 1)log2x=6 −2 x

15) x − 1¿

2 1+log6x −1

x+7=

1

2log6¿ 16)

4+x¿3

x+1¿2+2=log√2√4 − x +log8¿

log4¿

17)

logx− 1(x2− x ) > 2 18) log2x + log3x < 1 + log2x.log3x