!"#$%" &'()(*"+,-.,(/01&23 45 Câu I (2 đim)6&$&,-78 9 9 : /; /y x x m x= + + + + <=>?3&@+,: - ; /6 &A$7%3B,BC>?3&@&,-78D&(-E6 6 F-"&G"))(%3H@<I*->J>K'")3&L") /y x= + <M3>?3&@: - ;3N(9>(J-1&O".(P3:Q/;RSR 7*$<&$<%<3(T13UVT"<I*: - ;3N(SB,BU!"))=<BW("&*U6 Câu II (2 đim)6 1. (A(&P1&KX")3HF"& 9 9 9 9 x y y x + − = + − = 2. (A(1&KX")3HF"& 97("7("7(" =++ xxx Câu III (2 đim) /6 Y"&3&J3Y<&BZ33&J3H["\$*V7("&H*D&(]U*V&F"&1&L"))(W(&N".^(>K'")3H["3O-:Q;.%" DY"&E/]U*"&3H_<&$,"&6 6 H$")D&!"))(*"<&$&*(>(J-RS<8>@"&R>`a,(>$N"SE*b6\B,SV+,&*("c* >K'")3&L")BU!"))=<BW("&*UB,<d")BU!"))=<BW(S6He"\B,SV+fV&*(>(J-B,7*$ <&$E.:BW(.+,-`378<&$3HKW<B,.b*;6 *; g%<>@"&3O-B,.%"DY"&-h3<iU")$N(3(T13ja(P"S6 .; g%<>@"&B@3HY<I*B,7*$<&$3ja(P"S<=3&J3Y<&+W""&f36 Câu IV (1 đim).F-->J.f31&KX")3HF"&7*U<=")&(P-# 9 / : /; :/ ; /x m x m x+ ≥ + + − + 6 k#Mỗi thí sinh chỉ chọn câu Va hoặc Vb Câu Va (3 đim;6Chương trình cơ bản /6 H$")-h31&L")3l*>`4\VR<&$>(J-:9Q/;B,&*(>K'")3&L")<=1&KX")3HF"&+, / # / d x y− + = B, # 9 d x y+ − = 6m(T31&KX")3HF"&>K'")3&L")>(]U*B,3N$BW(&*(>K'") 3&L") / ,d v d -`33*-)(%<<O"<=>n"&+,)(*$>(J-<I* / ,d v d 6 6 H$")D&!"))(*"BW(&P3l*>`4\VoR<&$&*(>K'")3&L") / / / # / / x y z− + − ∆ = = − / 9 # / x y z+ − − ∆ = = − B,-h3<iU:;#\ pV po pq\rVpsoptE6m(T31&KX")3HF"&-h3 1&L")3T1\2<BW(-h3<iU:;>?")3&'(7$")7$")BW( / ∆ B, ∆ 6 96 F-1&i"3&u<<I*781&j< ( ) / i− Câu Vb. (3 đim).Chương trình nâng cao /6 H$")-h31&L")3l*>`4\VR<&$v+(1 : ;E <=1&KX")3HF"& / q x y + = B,>(J-:r/Q/; m(T31&KX")3HF"&>K'")3&L")>(]U*>(J-B,<M3 : ;E 3N(&*(>(J-RS7*$<&$+,3HU")>(J-<I* >$N"3&L")S6 6 H$")D&!"))(*"BW(&P3l*>`4\VoR<&$9>(J-:/Q9Qr;RS:QQ/;R:QQ/;6F-3l* >`<I*>(J-7*$<&$ pS p >N3)(%3H@"&w"&f36 96 (A(.f31&KX")3HF"& q Rt /s +$) q+$) q +$)x x x+ ≤ − xT3x :%".`<$(3&(D&!"))(A(3&Y<&)F3&e-; yyz OU { `(aU") (J- / / g|E ¡ u.(T"3&(e"#V}E9\ ps\p9E9:\p/; x≥ ∀ ∈¡ ,-78>?").(T"3He" ¡ ,-78D&!")<=<u<3H@ (W(&N"# +(- x y →±∞ = ±∞ SA").(T"3&(e" \ −∞ +∞ V} pp V +∞ −∞ ?3&@ V / r/4 \ t 9 t t / &KX")3HF"&&$,"&>`)(*$>(J-<I*>?3&@: - ;B,>K'")3&L")VE\p/ \ 9 p9\ p-\E 9 x x x m = ⇔ + + = K'")3&L")VE\p/<M3>?3&@: - ;3N(9>(J-1&O".(P3D&(B,<&nD&( : ; 9 g x x x m= + + = <=&*(")&(P-1&O".(P3D&%<D&(B,<&nD&( q q :; m m g m m ∆ > − > < ⇔ ⇔ ≠ ≠ ≠ :~; &(>=&$,"&>`<I*SB,3&w*-•" 9 6 B C B C x x x x m + = − = :/; *<=€}:\;E9\ ps\p-p/ P78)=<<%<3(T13UVT"3N(SB,+,€}:\ S ;E 9 s / B B x x m+ + + R€}:\ ;E 9 s / C C x x m+ + + %<3(T13UVT"3N(SB,BU!"))=<D&(B,<&nD&(€}:\ S ;6€}:\ ;Er/ ⇔ : 9 s / B B x x m+ + + ;6: 9 s / C C x x m+ + + ;Er/ ⇔ : 9 s B B x x+ ;: 9 s C C x x+ ;p:-p/;: 9 s B B x x+ p 9 s C C x x+ ;p:-p/; Er/ ⇔ : 6 ; /0 : ; 9s 9: /;:: ; 9: ;; B C B C B C B C B C B C B C x x x x x x x x m x x x x x x+ + + + + + − + + t t t xT3x :%".`<$(3&(D&!"))(A(3&Y<&)F3&e-; p- p-pE T3&•1BW(:/;3*>K•< - ‚tq-p9s-p9: ‚-r ;p- p-pE ⇔ t- ‚//-p/E ⇔ // / / m ± = 3&w*-•">(ƒUD(P":~; T3+UZ"#mW( // / / m ± = 3&F3&w*-•"VeU<iU6 t / / (ƒUD(P"# 9R 9x y≤ ≤ ≤ ≤ *<= 9 9 9 9 x y y x + − = + − = ⇔ :9 ; :9 ; x y x y y x y x − + − = − + − = :9 ; :9 ; :9 ; :9 ; x y y x x y y x ⇒ − + − = − = ⇔ − = ⇔ 9 9 x y x y = = = = (J-3H*3*3&fV 9 R 9 x x y y = = = = 3&w*-•"6 T3+UZ"#P<=&P<=&*(")&(P- 9 R 9 x x y y = = = = t t t t / *<= 97("7("7(" =++ xxx / $7\ / $7s\ 7(" c c x − − ⇔ + + = $7 $7s :/ 7(" ; $7 6 $7q $7 $7 : $7q $7 ; c x c x x c x c x c x c x c x c x ⇔ + + − = ⇔ + = ⇔ + = $7 c x⇔ = &$h<<$7q\p<$7\E $7 q c x x k π π = ⇔ = + R <$7q\p<$7\E $7q $7: ;c x c x π ⇔ = − s 9 x k x k π π π π = + ⇔ = − + T3+UZ"#&KX")3HF"&<=.*&l")&(P- q x k π π = + R , s 9 x k v x k π π π π = + = − + t t t t / / K'")3H["3O-:Q/;.%"DY"&E/<=1&KX")3HF"&#:\r; p:Vr/; E/ (ƒUD(P"# / 9x ≤ ≤ 6„1&KX")3HF"&>K'")3H["3*<= / / : ;y x= + − − BW( /y ≥ xT3x :%".`<$(3&(D&!"))(A(3&Y<&)F3&e-; m, / / : ;y x= − − − BW( /y ≤ 6 &J3Y<&BZ33&J<i"3F- ( ) ( ) 9 9 / / 9 / / / : ; / / : ; q / : ; V x dx x dx x dx π π π = + − − − − − − = − − ∫ ∫ ∫ h3\‚E7("3BW( x π π − ≤ ≤ 6 \E/ ⇒ 3E π − \E9 ⇒ 3E π a\E<$73a3R / : ;x− − E<$736 mZVmE q $7c tdt π π π − ∫ E :/ $7 ; c t dt π π π π − + = ∫ t t t t / *; l(+,3HU")>(J-<I*6 *<= RBN AB BN AM BN BM⊥ ⊥ ⇒ ⊥ \ a$>=3*-)(%<SBU!")3N(S7UVH*SE MN R 3KX")3uE MN 6 mZVESEEE MN E b O--h3<iU")$N(3(T1+,R.%"DY"&E b S .;h3E\bRSEVb *-)(%<SBU!")3N(S"e" ES pS V *-)(%<BU!")3N("e" E p UVH*. E E pS pS E\ p* pV |$>=\ pV E. ‚* D&!")>…(6 ja(P"S<=>%V+,SR>K'")<*$S6 &J3Y<& / / / *\ : ; : ; s / / V y a x y a b a= ≤ + = − 6 &J3Y<&3ja(P"S+W""&f3D&(ESE b a− 6 t t t t m / *<= 9 / : /; :/ ; /x m x m x+ ≥ + + − + : /;: /; : /; : /;x x x m x x x⇔ + − + ≥ − + + + (ƒUD(P" /x ≥ − xT3x :%".`<$(3&(D&!"))(A(3&Y<&)F3&e-; &(>=.f31&KX")3HF"&3KX")>KX")BW( / / / / x x m x x x x + + ≥ + − + − + ⇔ / / / / x x m x x x x + + − ≥ − + − + :~; h33E / / x x x + − + R.f31&KX")3HF"&:~;<=aN")#3‚3 m≥ :/; *<= † R † / 9 / : /; / x x t t x x x x x x − − + = = ⇔ = − + + − + − + 6 SA").(T"3&(e" \ r/ / 9− + +∞ 3} p r 3 9 9 9 + mZV // ‡ 9 Q /9 t + ∈ 6Sf31&KX")3HF"&>•<&$<=")&(P-D&(B,<&nD&(:/;<= ")&(P- // ‡ 9 Q /9 t + ∈ D&(B,<&nD&( // ‡ 9 ˆQ ‰ /9 *\ : ; t M f t m + ∈ ≥ BW(€:3;E3‚3 €}:3;E/‚3 SA").(T"3&(e" 3 / 9 9 9 + €}:3; p r €:3; / q „.A").(T"3&(e"# // ‡ 9 ˆQ ‰ /9 / / *\ : ; q t M f t khi x + ∈ = = mZVV<.33KX")>KX")BW( / q m ≤ t t t t m* 9 / / K'")3&L")>(]U*:9Q/;<=aN") # *\ 9 by a b∆ + − − = K'")3&L") ∆ 3N$BW(&*(>K'")3&L") / ,d v d -`33*-)(%<<O"<=>n"&+,)(*$<I* / ,d v d D&(B,<&nD&( / : R ; : R ;d d∆ = ∆ / $7: Ra ; $7: Ra ;c c⇔ ∆ = ∆ t xT3x :%".`<$(3&(D&!"))(A(3&Y<&)F3&e-; t: ; t: ; a b a b a b a b a b a b − + ⇔ = + + ⇔ − = + a b a b⇔ − = + &$h< a b a b− = − − 9 a b ⇔ − = &$h< 9 a b + = &l"*E9R.E/&$h<*E/R.Er96 mZV<=&*(>K'")3&L")3&w*-•"VeU<iU.,(3$%"9\pV‚/EB,\‚9VE t t t / mv<3X<&n1&KX")<I* / / / # / / x y z− + − ∆ = = − B, / 9 # / x y z+ − − ∆ = = − +i"+K•3+, :Q /Q/;R : Q/Q;u v= − = − r r 6h31&L"):;7$")7$")BW( / ∆ B, ∆ "&Z"<h1Bv<3X :Q /Q/;R : Q/Q;u v= − = − r r +,-<h1Bv<3X<&n1&KX")6 *<= ( ) / / / / Q Q 9Q sQ 9:/QQ; / / n − − = = − − = − ÷ − − r 6h31&L"):;<=aN") :;#\pVp-E6 h3<iU:;<=3O-:rQ/Qr9;B,.%"DY"&E96 h31&L"):;3(T1\2<BW(:;D&(B,<&nD&( : R: ;; 9 9 t / m d I P R m − + + = ⇔ = ⇔ = ± + + mZV<=&*(-h31&L")3&w*-•"VeU<iU+,\pVp 9 t EB,\pV‚ 9 t E6 t t t t 9 / *<= ( ) ( ) ( ) /q /q /q /q /q / / :/ ; : ; :/ ; :/ ; i i i i i i i − = − − = − − = − = − mZV1&i"3&u<<I*781&j<3He"+, /q t t t t m. 9 / / K'")3&L") ∆ >(]U*:r/Q/;<=aN") / / x at y bt = − + = + : a b+ ≠ ; RS / / / / A A x at y bt = − + ∈∆ ⇒ = + B, / / B B x at y bt = − + = + 6 +,3HU")>(J-<I*SD&(B,<&nD&( A B M A B M x x x y y y + = + = / / / : ; :/; : ; : ; a t t t t do a b b t t + = ⇔ ⇔ + = + ≠ + = RS : ;E∈ 7UVH*3 / R3 +,&*(")&(P-<I*1&KX")3HF"&q:r/p*3; p :/p.3; E9s q :q ; :0 /0 ; 9 a b t a b t⇔ + − − − = 6 3 / p3 E 0 /0 q a b a b ⇒ − = ⇔ − = 6&l"*E R.Eq mZV>K'")3&L")<i"3F-<=1&KX")3HF"& / / q x t y t = − + = + t t t t xT3x :%".`<$(3&(D&!"))(A(3&Y<&)F3&e-; / l*>`3Hl")3O-3*-)(%<S+,:/Q/Q; *<= ( ) ( ) ( ) S 9 : ; 9 MG GA MG GB MG GC MG GA GB GC MG GA GB GC MG GA GB GC GA GB GC + + = + + + + + = + + + + + + = + + + ≥ + + uuuur uuur uuuur uuur uuuur uuur uuuur uuur uuur uuur mZV pS p ≥ GA GB GC+ + afU.Š")\AVH*D&(B,<&nD&( M G≡ t t t t 9 / *<= ( ) q /s q Rt /s Rt q Rt /s q +$) +$) q+$) q +$) +$) q+$) +$) q+$) q +$) q +$) +$) +$) +$) +$) /s 0+$) +$) x x x x x x x x x x x x x x x x x − ≥ + ≤ − ⇔ + ≥ + ≤ − − ≥ + ≥ ⇔ + ≤ − + > 0 +$) t +$) sq / t / q x x x x x ≤ ≤ ⇔ ≤ − > ≤ ≤ ⇔ < ≤ Z1")&(P-<I*.f31&KX")3HF"&+,E sq / ˆ/Q ‰ :Q ‰ t q ∪ t t t t xT3x :%".`<$(3&(D&!"))(A(3&Y<&)F3&e-; . F-1&i"3&u<<I*781&j< ( ) / i− Câu Vb. (3 đim).Chương trình nâng cao /6 H$")-h31&L")3l*>`4VR<&$v+(1 : ;E <=1&KX")3HF"&