Đề thi tuyển sinh vào lớp 10 THPT (30)

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" P"?P;/?P5 " w ]∆Rw$D$fB#$E`$*')Z?Vj)?y)?^ 1 2 ' ' ( 2) | 1| 0,5 5 1 ' ' ( 2) | 1| 4 0,5 1 b m m x a m b m m x a − + ∆ + + +  = = >  −  ⇔ >  − + ∆ + − +  = = >   eK% 5 4 m − > .'],'[\$*.C]$'/5E`"$*')Z?,'i$W)Z.34Bfj$'\$8Q^ 6)Q/a35 5 !`T⊥/Tf6mn,.BKn$5 6T⊥!/*.5 ⇒!rr · · AOB ODC⇒ = /@f.5 G.0'2E.'}Ig$'E'h."mn,.BKn$Eo.$'+B.9)T8.+E`% · · AOB AOC= /Tf6m+,'i$*)2EEU+ · BOC 5 D$ · · ODC AOC= ⇒∆!Ei$.9)! 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"r!'IW)n.T!;~^7$'!8 ar)Y@•!Eo.T„^!'q$*?)$'^T;! " Câu IV%83 !'q$*?)$';: M L": a P": " L":P 0 ≥ 8Vj)?y)*)2.C>EU+:^ 2,2$ !iB rE`'+)$*')Z?:  ;"O: " ;8Q "rZE`$*')Z? ( )       = 9 14 ; 3 7 ; yx ar 055545125805 =−+=−+=P Mr] 0,01,011,1 ≥+≥−≥−⇒≥≥ bababa ( )( ) ( )( ) ( )( ) baabbaba bababababa +=⇔=−−⇔=−−⇔ −−+−+−=+⇔−+−=+ 1112112 1121111 !iB% r</5 "r'I6$'3J*)+I3)1?EU+/5V6/N5f6: " L"/L?5:La; +8E.C2)NhB'IGE '∆ ;/L?5 " Pav $D$,.fB#$E`'+)$*')Z?,'i$W)Z.Vj)?y)*)2.C>EU+? VeK/5V6/N5fB#$Eo.$'+B.9)'+)3)1?,'i$W)Z.Vj)?y)*)2.C>EU+? !iB 1 1 N M A O B C 1/ Chứng minh AM là a phân giác của góc BAC …!f6*`E$J)mn,E'o$EB$*! …f6*`E$J)mn,E'o$EB$* 6'+)EB$*!8WX$*$'+B.'}I*. D$…!;…'+KTf6,'i$*)2EEU+…! 2/ Cho biết AC = R. Tính BC, MB 0 90 ˆ =BCA /*`E$J)mn,E'o$$•+3[($*.Ck$N[($*07$'T58$D$.+?*)2ET!VB#$*.9)! &,N‚$*3>$'f€K.+*Ig$'3[tE 3RBC = +?*)2ET!34B/T;!;T!;~5 I3` 00 12060 =⇒= CBsđCAsđ  D$ RMBCBsđBMsđ =⇒== 0 60 2 1   3/ Giả sử BC cắt AM ở N. Chứng minh MN. MA = MC 2 +).+?*)2E!V6!T3=$*N9$*/ M ˆ %*`EE'B$*8 11 ˆ ÂC = /'+)*$.E'o$'+)EB$*WX$*$'+B5 BKC+^T;! " !iB % . AOC= /E?.5 %E'B$* ;!/;~5 D$∆;∆!/E*E5 ⇒;!O;! 6!;!/∆!Ei$.9)!5 D$;!;;! ⇒q*)2E!f6']$'.'I) a5 '}Ig$'E'h."mn,.BKn$Eo.$'+B.9)s8.+E`% KE=KC OE=OC(=R)  ⇒   sf63[($*.CB$*.C•EEU+p! D$s3)_B+.CB$*3)1?EU+3I9$.'H$*p! +K88s.'H$*'6$*^ n. Kỳ thi tuyển sinh Đồng Nai 2011 – 2012 Câu I%"8Q3 r)Y)": " La:L"; "r)Y)    =− =+ 032 73 yx yx ar$*)Y$W)1B.'qE 125805. ) ( ) ( ) ( ) xxxxx xxnênxxvì xxxxxxxx xxxxxxxx ∀≥+−+−⇒ ≥−+≥−>+ −+=−++=+−+ +−++=+−+− ,01222 0 1101 01 11211121 22121222 234 2 2 2 2 2 2222 2 2 324234