Tài liệu này là tuyển chon hơn 700 bài tập về bất phương trình logarit bao gồm nhiều dạng khác nhau giúp bạn đọc có thể tự rèn luyện khả năng cũng như kĩ năng nhận dạng các loại bài tập logarit cũng như bất phương trình logarit.
Trang 1BẤT PHƯƠNG TRÌNH MŨ VÀ LOGARIT
1 x x
x 2
2
2 log
log
3 3
1
3 10 3
x x
x
0 4 logx(log3(9x - 72)) 1
2
1
lnx x2 x 6 log2x2 2x 3y 8 7 y2 3y
2
3
2log 4 x 3 log 2 x 3 2
1 1
2 1 2 1 2
15 x x x
12 2 log5 x logx125 1 13 log 1 log 2 2 log 34 0
3 1 3
14 2 , 5 x 2 0 , 4 x1 1 , 6 0
3 3
1
3 10 3
x x
x
0 17 4 2 2 21 3 2 2 2 2 2 8 12
x x
x
18 lg 2 1
2
1 3
8 2
log x x 1
20 log93x24x21log33x24x2 21 logx1x 1 logx21x 1
3 2
3 3 3
2
log
2 log log
2 log 2
x
x x
x
1 3 2 5
5 lg
x x x x
2
3
2
3
x
x
x
x
27 2.2x3.3x 6x1
Trang 228
2
1 2
2 4
log 2
x
x
2 3 2 log 4 4
2 1 2
30 32x 8 3x x4 9 9 x4 0
31 9 x22xx7.3 x22xx1 2
32
x x
2
1 2
1
3 6
8
1 4
34 log5(12x)1log 5(x1) 35 2log2x log2x
36 log log9(3x9)1
) 1 3 ( log
1 )
3 ( log
1
2 2
1
) 3 ( log ) 3 (
3 1 2
2
1
x
x x
2
1 2
x
2
3
2 log 4x 3 log 2x 3 2
42
2
) 2
1 ( )
2
1
46 22x-1 + 22x-3 - 22x-5 >27-x + 25-x - 23-x 47 3 3 84
1 3 1
x
48 4 2 3 31 2 3 2 2 6
x x x
1 1
) 2 5 ( ) 2 5
x x
1
2
1 2
x
x
x
51 7x+7x+1+7x+2=5x+5x+1+5x+2
52 ( 2 1)x22x 1
x
15 34 9
25
2
x
x
56 4 2 3 31 2 2 3 2 6
x x
x
57 25x3x2 2x2x.3x 25x3x2 4x2.3x
3
1
(
3
)
3
1
(
1 1 2
x
4 2
3 4
4 3
3
5
4 0,5 21 0,5
62 (x2+x+1)x < 1
63 log4x-3x2>1 64 logx(x3-x2-2x)<3 65 log 4 6 0
5
x x
Trang 3
66 lg2x-lgx3+20 67 1+log2(x-1)logx-14 68 0
1 ) 4 ( log
5
2
x
x
5 4
) 3 (
log
2
2
x
x
x
70
4 1 log
7
1 log log7 x x
72
5
1 log 2 log
14
2 24 log
2
16
25x2 xx
3
1 2 log
2
x
x
64
1 log 12
1 2 ) 6 ( log 2
1
2 2
2 3
2 x
77
x x
x x
x
x 7 12 )(2 1 ) ( 14 2 24 2 ) logx 2
2
78 log log2log 19 0
2
2
1 2
2 4
x
x
80 log log 5 log ( 3)
2
1
3 1 3
82
4
3 16
1 3 log ) 1 3
(
log
4 1
4 3
) 1 ( log ) 1
(
log
2
3 3
2
x x
x x
85 logx 3(5x2 18x16)2
2 lg
lg
) 2 3
lg( 2
x
x
x
87 log 2x64 logx2 16 3
88 ( 1)log (2 5)log 6 0
2 1 2
2
3
1 (
] 3 ) 2 2 ( [log log 2 lo g 2 1 3
1 2 3
x
x
2
2 3
x
x
x 91 logxlog9(3x-9)1
3 ) 3
9
(
log
1
3
x
x
93. log9(3x2 4x2)1log3(3x2 4x2)
5 log ) 1 3 4
( 2 5 x x2
x
x x
96 log2x+log2x84 97 1logx2000 2
98 log (2 1)log (2 1 2) 2
2 1
2 1 2
2 log 2
) 5 ( log
) 35 (
x x
a víi: 0<a1
Trang 4102 log log ( 1 ) log log ( 2 1 )
5 1 3 2
5 2
1 x x x x 103 log2xlog32x + log3xlog23x o
104
x
x x
x
3
3 5
5
log
) log 2 ( log 3 log
2 2
2 4 3 2
6 5 5 log ) (
log 6
3 5 2
) 11 4 ( log ) 11 4 (
log
2
3 2
11 2
2
x x
x x x
x
107 2log29 xlog3 xlog3( 2x11) 108 0
1 3 2 5
5 lg
x x x
109 Cho 0 < a < b <1 CM BĐT: 2 2
ln ln ln ln
110
2
4
x
2
1 2
0
x
log
112
3
2log (4x 3) log (2x 3) 2 113 2
log 8 logx x log 2x 0
2
1 1 log 2
1 1 3 2
2
2 7.2 7.2 2 0
log 4 144 4log 2 1 log 2 1
x x
2 2
2
3
2 4 2 4 2 4 3 3
120 log log2x x2 x
4
2.x x2 x
2
11 6
x
x
x
15.2x 1 2x 1 2x 125 logxlog 93 x72 1
126 log log 2 1 2.
2 1 2
127 logx 1 (x 1 ) ( 1 )logx 1x 2
x
2
log x x
x
Trang 5131
2 6
1 3
1
x
x
132
x x
3 1
1 1
3
1
1
1 1
2 1
2
2 x x
2
5 , 0 5
, 0
2
2 5 08
, 0
x x
x x
136 log2 x log2x 8 4 137 log3 x log3 x 3 0
138 log1/3 log4 x2 5 0 139 log1/3 x 5 / 2 logx 3
140 logx 2 log2x 2 log2 4 x 1 141 0
5
3 4 log 2
2
x x
x x
2
1 log
3
x
x
6 log
1 2
log 2 log
2 16
x x
144 log 2 2 x 1
x 145 log log9 3x 9 1
2
2 3
x
x
147 log 2 3 1
3 x
x
x 148 logx 5 x2 8 x 3 2
149
1
log
1 1
3 2
log
1
3 / 1 2
3
/
log
1
log
a x
x
a
log
35
a víi x
x
a a
0 3
5 2
11 4
log 11
4 log
2
3 2
11
2 2
x x
x x
x x
153 log12/5( x 5 ) 3 log5 5( x 5 ) 6 log1/25( x 5 ) 2 0
154 log23 x 4 log3 x 9 2 log3 x 3
16 2
2
2 /
156 log2 x2 3 x2 1 2 log2 x 0
157 logcosx sin x logsin2x cos x 158 3x 9 3x 10 0
16
1 4
1
4
1
3
1 9 3
1 2/ 2 1/
161 52 x 5 5 x1 5 x
162 7 4 3 x 7 4 3 x 14
163 5 4x 2 25x 7 10x 0
x x x
Trang 6165 92xx21 34 152xx2 252xx21 0
166 log2 2x 1 log1/2 2x1 2 2
1 1
2 5 2
x x
1 2
1 2
x
x x
2 2
2 1 2
2
2 3
2 3
x x
x x
171 6 92x2x 13 62x2x 6 42x2x 0
172 log 2 . log 2 2 2 0
2
173 1 2x1 3x1 6x
174 25 2x 10x 5x 25
175 log2 x2 3 x2 1 2 log2 x 0
176 x 1 log12/2 x 2 x 5 log1/2 x 6 0 177 4 8 x1 2 x1 8
e x x e
x
178 4 2 3 31 2 3 2 2 6
x x
x
x x
x x
x
180
6
x x 2
2x 1 3x 1
2
x x
1 5 25
183 (x2 x 1)x 1 184
x 1
185 (x2 1)x22x x213
186 3x 9.3x 100 187 5.4x 2.25x 7.10x 0
188 x 11 1 x
190 25.2x 10x 5x 25 191 9x 3x 2 3x 9
8
3
log log x 5 0
5
log x 6x 8 2 log x 4 0
3
5
2
log log 3 9 1
198 log 2.log 2.log 4x 1x 2x 2 199 1
3
x
200 log2 x 3 1 log2 x 1 201 8 1
8
2
2 log (x 2) log (x 3)
3
2
log log x 0
Trang 7204
2
3 2
2
log xlog x1
2x
3x x
log 3 x 1
208
2
2 3x
x 1
5
2
3
x 1
210 log x22 log x2 0 211 x x
2 16
1 log 2.log 2
212 log x32 4 log x3 9 2 log x 33
2
log x4 log x 2 4log x
214
2
log x log x
3
2 log 2x log x 1 x
x
2
log 2 1 log 2 2 2
2
0
log x x 2 log x 2x 3 thõa mãn với 9
x 4
219
x
0
10 3
x x
x
Tìm n0 dương
221
3
2
5x x 1 223
1
5
25
x
224
40 1
4 3
2
2 2
1 3
3
x
225.22 1x 22x3 22x5 27x 25x 23x
226 51x 51x 24 227
7
2
2
1
7 7
x
3
2 log 2
229 52x1 5x 4 230.49x 6.7x 7 0 231.9x 2.3x 3
232 25 x2 2x 1 9 x2 2x1 34.15 x2 2x 233
234
2
log log
6 x x x 12 235 8logx 19.2logx 6.4logx 24 0
Trang 8236 5.36x 2.81x 3.16x 0 237 2.(5x 24) (5x 7) (5x 7)
238 13x 5 2(13x 12) 13x 5 239 4 2 4
2 1
x
x x
241
1
1
5
x
243 4 x2 x 2x21 3.2x2 x2.2x2 8 x 12 244 8 2 3 x 1 4 3x 2 3 x 1 5
245
2
log log 4
10000
2 1
x
247
2
1
2
log 3
2
x
x
249 2 6 8
x
x
253 52x 52 2 x 26 254
x
x
256 9x 4x 2.6 x 257 9.9x 25.12x 16.16x 0
258 62x 3 4x x 6.22x 259 5 32 2x 3 52 2x 34.15x
260
x
>0
2x 2
x
0
x x
262
2x
2
0
x x
>0
x x
264 32x2 2x 128.3x2x 9 0 265 22x2 4x 24.22x x 2 1 2 0
266 9x2 x 110.3x2 x 2 1 0 267
2 2
2
x 2 1
3
x x x
268 32x+122x15.6x 0 269 23x+17.22x 7.2x 2 0
2
3log (x2)6log (x 1) 2
Trang 9273
log (x 1) logx 64 1 274
3
log (134 )x 2
275
2
1
x
2
1
x x
277 1
4
log
x
x
1 2
log 1 x x 4 0
1
5
3
1
3
x x
281 log (22 x x2 1) 1 282
log x 6 log (x4)
283
1 log ( 8) log ( 4)
285
2
log (3 2 ) 1
8 2
x
x
x
2log xlog x4
3
2
7
3
2
25
2 lgx (1 2) lgx 2 2
(log x) 32(1 3)log x 302 2
4
log (2 x) 8log (2 x) 5
303 2
5
log (6 x) 2log (6 x) log 270 304 2
2 log 1
2
x
2
log ( 4 11) log ( 4 11)
0
2 5 3
2
log ( 2 7) log ( 2 7)
0
3 13 4
Trang 10307
2 2
5
x
x x
5
log (6x 36 )x 2
309
2 3
3
4
311
2
2
log x64 log 16 3
x
log (5x x 8x 3) 2 314 2
3
1 log 5 6 log 2 log ( 3)
2
x x x x 316 2
6log 1 x log (x 1) 5 0
317 log (90.5 x1 1) 2 log (30.5 x17) 318
2
2 log log 2
x
2
log ( 1) log ( 1)
0
log (3x 4x 2) 1 log (3x 4x 2)
321 (4x 12.2x 32)log (22 x 1) 0 322
2
1 1
3 3
log ( 1)
323
2
2
0 log (2x 1) log x 3x 2
1
x x
3
log (2x 3x 2) 1 log (2x 3x2)
32
8
x
x
328
log log 2 log 1 3
2
2
2 3
1
1 3
x
x
3
331 log x log x log x 1 3 9 27 332 2 2
lg x 3 x 7 lg x 10
2
3log x 3log 3x log 2
2
x
4
337 2lgx 3lg100x 2 2lg10x 2 338 lnx +2lnex-lne x lne 2 3
339 3logx 3log10x 2 log100 2log100x 340 log x 3 log x 1 3 2 2
Trang 11341 log x 3 log x 12 2 log 5 2 342 log x log x 1 1 2 2
343 ln x+1 ln x 3 ln x 7 344 log 2x 22 log 24 2x 2
345 2 2
1
log 2x 4 1 log 1 x
347 1 1
352 log x log x 32 2 2 353 2ln x 3lne x lne 0 2 2
100 log x 10log x 6 0
356 log x log 7 log 49 7 x 7 357 log x log 2 log 4 2 x 2
358 x
2
3
360 x
2
5-lgx 1 lgx
7
364 x
2
log ( ) log 9.log 4 log
3
x
367 log log 22x 2 xlog2xlog 42 x
368 log 64 log 162x x2 3 369
2
log 3l ogx+3
1 log 1
x x
4
log (3 1).log
x
371
1
( 5 2) ( 5 2)
x
( ) ( )
x x x
373
1 2
2
16
x
x
2x 2x 2x 3x 3x 3x
375 2 3 2 2 3 3 2 3 4
2x x .3x x .5x x 12 376
( 10 3) ( 10 3)
Trang 12377
2
5 6
3
3 x x x
2 x x 1
x
( 2 1) ( 2 1)
x
382 2
1
3
3
x x
x x
383 2
1 x 1
x x 384 9x 2.3x 3 0
385 2 6 7
2 x 2x 17 0 386 3
2 x2 x 9 387 2.49x 7.4x 9.14x
4x 3.2x x 4 x
6.9 xx 13.6 xx 6.4 xx 0 391 2 1 2
4x x.3 x 3 x 2 3x x 2x 6
392
2
1
x x
x x
2 2
2
3
x x
x x
1
395 1 2 1 2
x
2
2.3 2
1
x x
x x
2 1
x x
16
x
399 log (3 2) 1
2
x
x
x
3
2log (4 3 ) log (2 x x 3) 2
401
2
4
x
x x
1 log 5 6 log 2 log ( 3)
2
404 logxlog (93 x72)1 405 2
log (5x x 8x 3) 2
406 log 64 log 16 2x 2 3
x
2
2
lg lg 2
x
4 2x 3.2x .2x 8 12
409
6
x x 2
2x 1 3x 1
2
x x
1 5 25
412 (x2 x 1)x 1 413
x 1
(x 1) x 1
415 5.4x 2.25x 7.10x 0 416 x 11 1 x
417 52 x 5 5 x 1 5 x 418 25.2x 10x 5x 25
Trang 13419 9x 3x 2 3x 9 420 2
5
log x 6x 8 2 log x 4 0
3
5
2
log log 3 9 1
423 log 2.log 2.log 4x 1x 2x 2 424 1
3
x
425 log2 x 3 1 log2 x 1 426 8 1
8
2
2 log (x 2) log (x 3)
3
2
log log x 0
429
2
3 2
2
log xlog x1
2x
3x x
log 3 x 1
433
2
2 3x
x 1
5
2
3
x 1
435 log x22 log x2 0 436 x x
2 16
1 log 2.log 2
437 log x32 4 log x3 9 2 log x 33 438 2 4
2
log x 4 log x 2 4 log x
439
2
log x log x
3
2 log 2x log x 1 x
x
2
8
log x 4x 3 1
3
log log x 5 0
x
0
3
2 0,7 6
4
x
log 4x 144 4 log 2 1 log 2x 1 450
2 1 2
x
451 log0,55x10log0,5x2 6x8 452 log2x3log2x21
Trang 14453 log2x3x21 454 0
1
1 3 log 2
x
x
455 2x2 4x1
4
1
x
457 log 1 log log9 1
9 1
3
459 log4 x3 1 460 152x + 3 > 53x + 1.3x + 5
461 6log x xlog6x 12
2
6 462 2x 3x1 5x2 12
463 3x 3 x2 8 0
464 log22 x log24x 4 0
1 1
1
9 4 6 5
4
.
9 466 4 x25x 2 x25x2 4
2 3 2
log 4 4
2 1 2
1 1
2 2 3 2
2
x x
469 1 lg lg 2 lg 2
3 2 6
4 x x x 470 log4x2 23log4x1
x
471 logx125x log225x 1 473 x2 logx27 log9 xx 4
474
1 3
1 5
3
1
1
x
2 log
2 log log2
a x
x x
a
a a
476 4 log 3x 243
x 477 32lgx 3lgx25 2
478 6 9 x2x 13 6 x2x 6 4 x2x 0 479 x
3
2 1
10 1
10 log3x log3x
x 1
1 x
2
481 log2logx3 log3logx2
482 logx 1 (x 1 ) ( 1 ) logx 1x 2
x
6
1 3
1
2 x
x x
3 1
1 1
3
1
1 1 2 1
2
2
xx
487 log log 2 1
5 , 0 5
, 0
2
2 5 08
,
0
x x
x
2 1 )
1 (
489 log3x log3x30 490 log1/3log4x2 5 0
491 log1/3x 5 / 2 logx3 492 logx2 log2x2 log24x 1
Trang 15493 0
5
3 4 log 2
2
x x
x x
2
1 log
3
x
x x
495
6 log
1 2
log
2
log
2 16
/
x x
497 log log93x91
2
2 3
x
x
499 log 3xx23 x 1 500 logx5x2 8x 3 2
1 1
3 2
log
1
3 / 1 2
3
/
log 1
log
a x
x a a
5
log
35
a víi x
x a
0 3
5 2
11 4 log
11 4 log
2
3 2
11 2
2
x x
x x x
x
505 log12/5(x5)3log5 5(x5)6log1/25(x5)20
506 log23x4log3x92log3x3 507 4
16 2
2 2 /
508 log2 x2 3x212log2x0 509 logcosx sinx logsin2xcosx
8 15 4 15
4
x x x
511 92xx21 34 152xx2 252xx21 0
512 log22x 1log1/22x1 2 2
1 1
2 5 2
x x
1
2
1 2
x
x
x
515 3 5 3 5 2 2 0
2 2
2 1 2
2
xx xx xx
2
3
2
3
x
x
x x
517 6 9 2x2x 13 6 2x2x 6 4 2x2x 0
518 log2x22.log2x220 519 x 1log12/2x2x 5log1/2x 6 0
520 4 8 x1 2 x1 8
e x x e
x x x
x x
x x
x
523 25x3x2 2x2x.3x 25x3x2 4x2.3x
524 1 log 3
81
x
log (x 3 )x log (3x 1)
x x
2 2
2
3
Trang 16528 3x + 1 – 22x + 1 – 12x/2 < 0 529 log25x2log5x150
530 log (3 x 1) log (113 x) 3 531 2 1
log 4x4 log 2 x 3.2x
532 log (log (93 x 72)) 1
log (4x 144) 4log 2 1 log (2 x 1)
534 3 9
3
4
1 log
x
x
x
log 8 logx x log 2x 0
2
log x 4.log x 2.(4 log x )
2 4
log log x 2x x 0
539 log 5 5 x 4 1 x
3
2 log (4x 3) log (2x 3) 2 541
3 2
4 3
2 3
2 2
x x x x
x
x
2 1 2
2
3 2
2 1 4
8 log
0 4
3
1 log 1
log
2
3 3 2
x x
x x
1
x x
1 log log
1
x x
546 log 5 3x 4 log 5 1 x 547
3
x - 2
x
548
2
(log x) log x
1 log x 5x 6 +log x 2 log (x 3)
2
550 log x2 log x-12 log x - 22
2 1 2
x
2
1 2 log
6 5 log
3 1 3
1 2
) 1 ( log
1 1
3 2 log
1
3 1 2
3
1
3 2
x
x
5
x
x
556 1+log2(x-1)logx-14
1 ) 4 (
log
5
2
x
x
5 4
) 3 ( log
2
2
x x
x
559
4 1 log log29 x 23 x
7
1 log log7 x x 561
5
1 log 2 log
Trang 17562 logx2.log2x2.log24x>1 563 1
14
2 24 log
2
16
3
1 2 log
2
x
x
565
64
1 log 12
1 2 ) 6 ( log
2
1
2 2
2 3
2 x
2
567
x x
x x
x
x 7 12 )(2 1 ) ( 14 2 24 2 ) logx 2
2
568 log log2log 19 0
2
2
1 2
2 4
x
x
570 log log 5 log ( 3)
2
1
3 1 3
572
4
3 16
1 3 log ) 1 3
(
log
4 1
573 log12x4x284x5 0
4 3
) 1 ( log ) 1 (
log
2
3 3
2
x x
x x
575 logx 3(5x2 18x16)2
2 lg lg
) 2 3
lg( 2
x
x x
578 ( 1)log (2 5)log 6 0
2 1 2
2
3
1 (
] 3 ) 2 2 ( [log log 2 lo g 2 1 3
1 2 3
x
x
2
2 3
x
x
25 1 5
5 2
5
16
31 2 ( log
log2 0,5 x
583 log2x4 32
1
2 lg 2
1
2 lg 4
2
2 2
x x x
x
3 ) 3 9
(
log
1
3
x
x
586 log9(3x2 4x2)1log3(3x2 4x2)
5 log ) 1 3 4
( 2 5 x x2
x
x x
588 log2(2x+1)+log3(4x+2)2 589 log2x+log2x84
590 1logx2000 2 591 log 6 log 3 log ( 2 )
3 1 3
1 2
592 log2(2x 1)log1(2x12)2
593 log22 xlog1 x2 3 5(log4 x2 3)