Bài tập trắc nghiệm Lũy thừa 20162017

-a LU? T}IUA L [l- 1)-o'" It\-: ta duoc: | +l, \16' \,8/ Cflu1: Tinh: K = A I Cflu2: Tinh: K = 1o-3 : 1o-2 A c B 16 2'.2-t +5-3.5* L2 10 @ro 18 , ta duo c -(o,zs)o c t2 @to ,/ D 15 1\' 2:4-2 +(3-' )' I \ /lol\),/ t-' ,.taduoc C*u3: Tinh: K = (r)-' 5-'.25'+ (0, z)o l-l \2) I B.- (A) \_/ -13 I c.- -J n.? a J CAu4: Tfnh: K = (0,04)-''' - (0,125)-l , ta duo c \/ ( C 120 A.90 CAuS: Tinh: K A.z ,Y = 87 : 8J121 D 125 3i - 31.3i 8.3 duoc @i D.4 C6u5: Cho a li mdt sd duong, bidu thrlc ul Ji vidt dudi dang lu! thila vdi sd mfr hftu t!, lil: j 5_ (a) \-/ uu B o a6 ^-= cAuT: Eidu thrlc u',11u] vidt i^2si dr-r-oi C dang lu! A.aI (9u, cauS: Bidu thfc Ji.fi.{/t' 7_52-5" A xr B A cflulo: = Vx Ch_o Khid6 f(x) = Cflul2: Tinh: K s - i rf t}: \' *l bang: D o,4 fr!'l bdne: 10,/ a [ rb) 13 B.'^ @ 2,7 j' Cu) G/,3 \-/ 10 Cflult: ln: D.al c xl il A.t $ Khi d6 f(g.S?) J*.}', ttrrra vryi sd mfl hfru (x > 0) vidt du6i dang ru! thira v6i sd mfi hffu '!:P o,1 V;.V; Cho fix) I D a7 C.aE xi Cflu9: Cho f(x) = il D.4 10 fifi'dt' Khid6 f(Z,1)bang: 8.3,J C 4,7 D 4s+J1.2r-dz 2+*Ji, ta duo c: 8.6 c.7 5,1 ' A (D) i CAul3: Trong ci{c phuong trinlr sau dAy, phuong trii6 n}o c6 nghiOm? -1l:.xl A x6 + B C xi +(x-r); =g @ ^Ciul4: M€nh dd nio sau dAy li i: 1=0 o Jx-4+5:0 dring? (f -Jr)- (S -Jr)' (r-J7)' lr-Jl) t / r-\3 i CAu15: Chon m0nh dO r-tl B (*1 -J7)' , (J" -r3 (d(^ -.,0)' dring c6c m0nh dri sau: -.,D (+-Ji)^ I i i -t=0 A 4-J5 > 4-'5 Carr16: [i)" [;) B 3r'r < 3l'? Cho;" >;'t l{ t lilin ii}i;.liu iial,iii drirrg? A.cr 0), ta duoc: (9'r'* :23 Khi bidu th(rc K = sl22 :,fii nVG*i,/+ p tB+{/a c (b > 0) duoc: (c, u' D b4 b x.{"x' :x'n -+ V, to > 0), ta duoc: C ti ta duoc: 1'/I-r II \u) Ciru27: Rtit gon hieu thuc 6{r: A b B br CAu28: RLlt gon bidu thr?c J-; 1/< s i/i * uut I D.creR C.cr3 CAu25: Truc cdn thttc & mAu bi vir a+ 1,x i')r y li C 1og" B y (* t y) = logn x + 1og Y loe "" l= x fg: CAu4: 1og, ii ; a' (a > lof" x log x = logn a.log [D, \_/ c.- D.2 c.'5 D.4 1) trirng: (n.-\J3 CAuS: a+ B J J log, {52 bang: I -'s A B.- @; D.3 CAu6: 1ogr,0,125 b[ng: - A4 6;' c.2 D.5 / :r,t::fJ\ C5ru7: los i l1i 11- | brng' \' '\a ) B L? @: q c.- D.2 @+ D.5 (c 1000 D 1200 c.4000 D.3800 c.50 6,, CAuS: 49to'tt2 bang: A.2 8.3 -' bzing: 200 ts.400 L ios, to CAu9: 64: A Cau10: _10'o218' bang: fA)+qou \/, caull: oiros:3+3luers A.25 B.42oo bing: 8.45 a+ 1, h > 0) bang: CAu12: u3-21os"b ac a'b' B (ry Caul3: Ndri iog- 243 = thi x bang: (a > 0, utu' H.^ L a'b @ -,3 (x > 0,n * 0) C&u3: 1og tT bang: A-l x hai sd dtrong Tim mOnh d0 dfing c6c m0nh cld sarr: x losx A Ioc aa -:ry log, ro*" xn = nlog c.4 D ab2 D.5 x ' \ =-4 c&u14: Ndu iog, ztr{i @# Ciul5: rhi x bang: c.4 B 12 D.5 3logr(logo 16)+1og, bang: >\? B"3 IAI2 \-/ C.4 CAu16: Ndu log, x = llogu9 -log" A.? 55 Cflul7: Ndu D.5 I * = +1og" (a > 0, as r.1 1og" a* 1) thi x b[ng: D.3 -5 ua -31og l(1ogua 4) (a > 0, a* 1) th) x blng: 2' A 2J' B @ u'a' B J' c.8 D 16 CAu18: Neu 1og, x =51ogz a+4logrb (a, b >0) thi x bing: aab' c 5a + 4b D" 4a + 5b Caul9*d{€u log, x = 8*g, ab) -ZIog, a3b (a, b > 0) thi x bang: A aob6 (BJ a'b'o C a6b', D arb,o CAu20: C}o$2 = a Tinh 1925 theo a? 4.2+a 8.2{2+3a} C&u21: Cho lg5 = a Tinh tgf "64 4.2+5a @r,,-, tneo at B 1-6a Cilr.Zh: Cho lg2 = a Tinh WEitheo "4 C.4-3a @ 2a-1 a jt,,.r) tl-reo a li: : C-Za+3 a+1 Cau25: Lfho log.5 = *; Iog, -= b Khi ct,i logu tinh theo A CAu26: OjL -]a+b Gii A Ztos,(a+b)=log: C log, Cim27: log* A.E CAu28: Vdi c -a+b sri ta c5 h0 thric a2 + b2 = 7ab a+ a b- T 8.1ogo gi;1 D 4log, vl ulo 81 bang: tri nlo c,ia x rhi bidu @ o 0) H0 thrlc nlo sau day a+log,b Z{togra ,D.2-3a v) b th: o rL = n a_u.vd-: 4') ii: B.u a-l ry fl.6+7a C.2(5a + Cau24: Cho log,6 = a " Khi iog.i8 tinh 1tr \, @o1u- a? Ceu23ICho logr = a Khi d6 logo 500 rfnh theo A.3a + D 3(5 - 2a) i, i lD.xOkhix>1 B 1og^x2 C.9 8.2 + rn + = ts 36 c trinh: krg, x + 3log, s} 45 2= 1l c6 nghi0m @ uo c6 rAp nflhi0m ii'r: li: r {+; :} c {+; io} D q) CAu18: Phuong trinh: 19 (x' - 6x+ t) = fg (x - :) c6 tAp nghi0m th: n {:; +} c {+; s} D.O @tir) la C&u19: Phuong trinh: i + = = c6 t6p nghi6m li: (ry {z; 4-lgx 2+lgx (D @ 1ro, rool n {t;:o} {to; {tc; Do {*','} Cf,u20: Phrrcrng trinh: x-2*rog' = 10[]0 c6 tip nghi€rr l]r: r lr I zo} r too} / C 1-: 1000 ! a w ltO D.@ ) C&u21: Phuong trinh: iog" x + iog* x = -? c6 tAp nghiOm lh: c {z; s} @tot B {3} A{3} (yVl C6;u22: Fhuong trinh: og, x = D rt; -x + cti tAp nghidrn ih: c{z:s} DCI ^ - HEPT{LIoNG rRiNH ntfi vi leicenir l) )' *I Caul: I:10 phuong tiinh: l;-:: o:' vdi x > y c6 mdy ngiri6m:' x' - sK \L -L) /' 8"2 c.r cau2: CAu3: Fle phuong tri'h: a) A (3; I-16 phuohg tr)ntr: i) B eAus:[i0phuorrgrr;*, (a; a (roo; * [4'*" 16 17^+y =4 -3) tri"h, - :) a (:: a (4; +), (r; (zo; t+) (+: +) D3 z) o (s; -:) g,i(r; uoi xzycongiriem ]:*t:7 +lgy:1 t) _ Q(s; llsxv=5 _'.rr, = 6'tai n (soo; iil z) a @ t+, z) c s) B (2, ia'] D Kdt qua kh6c )'y cd nghiern +) =-20 C0u9: He phuong tri,,t,' o nghiOm th: ' yt rrinh: ,) 92 ".,,,1 - =O.j 1.,:+ I ^, (+: D.0 c6 may nghi0m? ] n (o; ro) He phuong a @)(r' v l'x+2v=-l [trgx :) CAirS: FIo phuong ciu7: 3) L' G c6 nghiem th: 1* _ u.r, +z = a BI CAu4: H0 phuong trinh: a i3t''-2'=5 B (rr Ao e (z; c.3 = @ lb? irooo, ,oo1 , 'D Kdrquikhdc ^ v6i x z y c6 nghiem lh: llogrx+log,y=3 {:t {* -' (:v?: ,i: ) +),(zz:o+) c (+' 16) (s: i6) U , D Kel quri kiidc i.ln x + 1n y = 31,,6 ,,,fu,J(o' t),(z;z) t6 *ghi€m ld: n (tz; o) -= 5^ c' (s; z) nghiorn l) caur0: rre phucrns rri,.,n, {31t 11" [4lgx+3lgv=18 (b) I.' t' qrr; iz; * { a (roo; tooo) c roo) @ioco; D Kdt qui khdc (so; +o) s{r pHU4Nf rRiN.H MU vA l0cnnir CAul: Tap nghiom cua bdt phuong rrtnn' [-f ]^-' \2) a r) (o; " [,'il \,4) (z;s) r [-z;r] cau3: Bat phucrng ^ *,"n' \2) LJr)' @) c6 tflp nghiern 1): [-r':] , D Kdt qui kh6c c6 tap nghiem [])" [;)* B [*.o;2] c (o; 1) /\ Q! [t; z] D CAuS: Bdt phuong +) trin!: 9- -3^ -6 a (r;**) Ciu6: fft (.d < 1): @ (-*, r; B (1;+"o) c (o;r) n (-i;r) phuong trinh: 2- > 3'c6 tip nghi0m (-*;o) @ @ (-*'log,3) c6 tflp nghi0m c (-t;i) l]: li: Cflu4: BAt phuong trinh: 4^ 27-;, c6 tflp nghiem li: l3o r A [2: +co) Zl C (-co; I ] D 12; 5l @f Z; C&u8: BAt phuong trinh: log, (:x - Z) r log, (e -:x) c6 tAp nghiem l): CiuT: Hc bdr phuong CAug: Bdt phuong trinh: logo (x +-7) > 1og, (x + 1) cd tip nghiem a (l;4) (s;+"o) B Cf,ult): Sd gini bat plutong trrnh: Budcl:DiduL16n, @t-r;zs A>o e [.'? x-l Budc3: 1v '^ x-l In 1) I ln il, , O i*) mot hoc sinh lap luAn qua ba brrryc nhu sau: ;t_l Lx>l Budc2: Ta c6 D (-m; li: 1u > x 1ex - ln '^ x-l > ,r, lnl 1u e 'n > | (Z\ x-l >-1 (3) Kdt hqp (3) vh (1) ta duoc [-1