(Đề thi có 01 trang) !"#$%&!'()* Thi gian lm bi: 180 pht, không k thi gian giao đề +,(2,0 đim) y x x mx= − + − !"# $%&'( ( ) )+∞ +,(1,0 đim) *'(+'(' ',-./01 ( ) ( ) ( ) #A B C B C A C A B− + − + − = 2345'(% 6 76 6 # x x − + = +,-(1,0 đim)$8839 ( ) : # . ;I x x dx= + ∫ +,(1,0 đim) 2345'(% 7 #x x− + = (<3=33* $%>'?0'* @?? (&&/* ( ) 6 #x x x − ≠ ÷ +,(1,0 đim)$('?0'' A@BC4D'E'FG x y z+ − − = = − HI3E' JG@KBLCK"#$%M N' &O FJ$8?'PQJQ /NFOQ" 7 +,. (1,0 đim) .R' (S*',-,T-TT 1 ',-/0' 9 > -H ,-" T" $8U &8?.R'(S,-,T-TT8'1'V -T!I3E' ,T,T +,/(1,0 đim)$('I3E'A@B%V<,-W1FX8.H4D' E',-1345'(%.G@L:BL"#H4D'E'-W1345'(%.@KBK"#$% M NY,H-HHW +,0(1,0 đim)2Z345'(% [ \ [ x x x x x+ − > − + − + − + +,1(1,0 đim)@HBHC] ^G@ LB LC " $%'(.!ZH'(]Z &/*J"@ LB LC _@BC ''''''''2"''''''' 34"5!$66666666666666667789:&%;<!$6666666667 #&"=$6666666666666666#&"=$6666666666 >> 9/ ` Ja.4= b& 1 (1,0 đim) $' 2 (1,0 đim) 1$cbGd e 7y x x m= − + #H6 f'( ( ) )+∞ ?Y? ( ) e # )y x≥ ∀ ∈ +∞ ( ) 7 )x x m x⇔ − ≥ − ∀ ∈ +∞ #H6 cgh@" 7x x− 1' @ −∞ L ∞ BT K#L B # K #H6 R*'1 ( ) 7 ) # #x x m x m m− ≥ − ∀ ∈ +∞ ⇔ − ≤ ⇔ ≥ ./< #H6 1 (0,5 đim) 1 ( ) ( ) ( ) A B C B C A C B+ − = − ( ) A B C= − A B A C= − -i45'1 ( ) B C A B C B A− = − ( ) C A B C A C B− = − N'1j/3*' 2 (0,5 đim) J45'(%45'45'! 6 6 6 76 6 # 6 x x x x = − + = ⇔ = #H6 # x x = ⇔ = #H6 bI ( ) . ; )u x dv xdx= + = #H6 1 ( ) ) ; ; x du v x x = = + + #H6 ( ) ( ) : # : ; . ; # I x x xdx= + + − ∫ #H6 6.6 ;. \= − − #H6 : 1 (0,5 đim) e ; # ∆ = − = − < #H6 J45'(%1 'X3*. ) x i x i= − = + #H6 2 (0,5 k>'i'l/('? (&. ( ) ( ) 6 6 # 6 k k k C x k x − − ≤ ≤ ÷ #H6 đim) ( ) # 6 k k k C x − = − k>'?0'* @*'!#K?"# #k⇔ = k>'1.#[6#[ #H6 6 (1,0 đim) b4D'E'F1345'(% . x t y t z t = − + = + = − cgX # x t y t t z t x y z = − + = + ⇒ = − = − − + − = H<B' &.OK)K) #H6 2M Q ( ) ) )t t t− + + − /N F 1 ( ) ( ) ( ) 7 7MN t t t= ⇔ − − + − − + + = #) t t⇔ = = − #H6 m!"#H&QK))H ( ) ( ) ) d N P = #H6 m!"KH&QK)K)H ( ) ( ) ) d N P = #H6 7 (1,0 đim) f%G 1FX8B. S a= $&8?.R'(S V a= #H6 2Mf.(/'&,H 1-f/0''1!, m% I3E',-,T,T/0''1-f/0''1 !,T,T m<BfT.%/ -T.I3E',T,T'1a %. · eBC H #H6 1-f" a e B C a= #H6 $ '/0'-fT1 · · # e e # e BH BC H BC H BC = = ⇒ = ./< #H6 [ (1,0 đim) cgXG : # # x y x x y y + + = = ⇔ − − = = − H<B-)K #H6 1 '1 'V 4D' E' ,-H W- +' '1 · : 6 6 6 6 ABD − = = · · 6 6 AD ADB ADB AB = ⇒ = = #H6 OFX8,-W. S AB AD AB AD= = ⇒ = $PH'X1,-"H,W" 2M W ) KH 1 ,W" ( ) 7 ) : 6 a a d D AB a = − ⇔ = ⇔ = ⇔ = − 2Mn.(/'&,-W #H6 m! "7HW7);b4D'E',WG:@KBL"# [ ) ) ): 6 6 A I − ÷ ÷ H /B( \ ; ) 6 6 C ÷ m! "K:HWK:)K$45'1 \ :; ) ) ) 6 6 6 6 A C − − − ÷ ÷ #H6 \ (1,0 đim) bj/?X [x≤ ≤ -J$45'45'! ( ) ( ) ( ) [ [ #x x x x x− − − − − − − − > #H6 ( ) ( ) ( ) ( ) [ [ # [ # x x x x x x x x ⇔ − − − − − − − − > ⇔ − − − − − > #H6 6 : x x > ⇔ < =3j/?X1'X. [ ) ( ] ): 6)[x∈ ∪ #H6 ; (1,0 đim) L$ 1 P x y z x y z xy yz zx x y z x y z P x y z x y z x y z x y z P x y z x y z = + + + + − − − + + − + + = + + + + + − + + + + = + + + = + + + #H6 LbI@LBLC"H 7t ≤ H 4=G P t t t= − #H6 L e # P t t= ⇔ = ± HJ 7± "#) P − = − ) P = #H6 LoG @ ) M P MinP = = − #H6 . (Đề thi có 01 trang) !"#$%&!'()* Thi gian lm bi: 180 pht, không k thi gian giao đề +,(2,0 đim)