Ôn Tập Toán 10 Phần Đại Số

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  • 8/12/2019 n Tp Ton 10 Phn i S

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    I. Phn Hm S

    Bi 1:Biu din cc tp hp sau trn trc sri cho kt qu:

    1) 3;3 ( 2;1)

    2) ;0 3;

    3) 1;3 0;6

    4) 3;3 \ 1;5

    5) 3;2 1;3

    6) \ 0;3R Bi 2:Tm tp xc nh ca hm ssau:

    1)

    2)2

    7

    2 3

    xy

    x x

    3)

    4)

    2 3

    2 3 2

    xy

    x x

    5) 2 2 1y x x

    6)1

    3 21

    y xx

    7) 3

    41

    y xx

    8)

    1, x 3

    2 1

    4 , x< 3

    xy

    x

    Bi 3:Xc nh tnh chn lca cc hm ssau:

    1) 4 23 2y x x

    2)1

    y xx

    3) 33 4y x x

    4) 3y x

    5)1

    2

    xy

    x

    6) 2

    3y x

    7)3

    1

    xy

    x

    8) 1 1y x x

    9) 2 23 3

    x xyx x

    Bi 4:Tm gi trca hm s:3 8, x < 2

    ( )2 1, x 2

    xy f x

    x

    ti cc im x = -3 ; x = -2 ; x = 0 ; x =

    Bi 5:Xc nh hm sy = ax + b bit ng thng i qua hai im M(-1;3), N(1;2)Bi 6:Xc nh hm sy = ax + b trong cc trng hp sau:a) ng thng trn ct ng thng y = 2x + 5 ti im c honh bng -2 v ct ng thngy = -3x + 4 ti im c tung bng -2.

    b) ng thng trn song song vi ng thng 12

    y x v i qua giao im ca hai ng thng

    11, y 3 5

    2y x x

    Bi 7:Xt sbin thin v vthca hm s: 1 2y x

    Bi 8:Cho hm s: y = x + 2a) Xt chiu bin thin v vthhm s: y = x + 2.

    b) Tm giao im ca thhm sy = x + 2 v thhm sy = -3x + 1

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    c) Da vo thtrn vthhm strn hy vthhm sy = 2x

    Bi 9:Xc nh hm s: y = 2x2+ bx + c bit rng thca na) C trc i xng l ng thng x = 1 v ct trc tung ti im M(0;4)

    b) C nh l I(-1;-2)c) i qua hai im A(0;-1) v B(4;0)d) C honh nh l 2 v i qua im N(1;-2)Bi 10:Xc nh hm s: y = ax24x + c, bit rng thca na) i qua hai im A(1;-2), B(2;3)

    b) C nh I(-2;-1)c) C honh nh l -3 v i qua im P(-2;1)d) C trc i xng l ng thng x = 2 v ct trc honh ti im Q(3;0)Bi 11:Cho hm s: y = -x2+4x -3(P)a) Xt sbin thin v vthhm s

    b) Tm giao im ca (P) vi ng thng (d): y = -x + 1

    c) Da vo (P) hy vthhm sy =

    2

    4 3x x d) Bin lun theo m snghim ca phng trnh: -x2+4x -4m = 0Bi 12:Cho hm sy = x2-2x +1 (P).a) Hy xt chiu bin thin v vth(P) ca hm s

    b) Da vo (P) vtrn hy vthca hm s: 2 2 1y x x

    Bi 13:Hy vthca cc hm ssau:

    a) 322 xxy , b) 2 4 2y x x , c) 2 1x y = x

    II.Phng trnhBi 1:Gii cc phng trnh sau:a) 2x -3x + 1 =0

    b) x4 + 5x2+ 4 =0c)

    d)2 1 2

    3 3

    x x

    x x

    e)

    f)3 1

    3

    3

    xx

    x

    g)1 2

    11 2x x

    k)1 3 5

    2 2 2

    x x

    x x

    h)2 2

    4 5 3 3( )

    3 5 3 2

    x xt x

    x x x x x

    k) 2 2(3 5) (3 2)x x

    Bi 2:Cho phng trnh: a) Gii phng trnh vi m = 3.

    b)Tm m phng trnh c hai nghim tri.c) Gii v bin lun phng trnh trn theo m.Bi 3:Tm m phng trnh sau c hai nghim x1,x2thomn:a) c

    b) ( ) c

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    c) c 5

    9

    d) c . n: a) m = 0;1 b) m =-3 c) 50/57 d) -13Bi 4:Cho phng trnh () Tm m phng trnh c hai nghim phn bit v tch ca hai nghim bng 8.Bi 5:Cho phng trnh ( ) c hai nghim

    .Tm m biu thc:

    P = t gi trnhnht.Bi 6:Cho phng trnh ( ) c hai nghim . Tm m biu thc:P =

    t gi trln nht.

    . n: m = 27/8.Bi 7:Cho phng trnh: x2- 2(m- 1)x + m2 - 3m = 0

    a) Gii phng trnh vi m = 2

    b) Tm m phng trnh c mt nghim x = - 2. Tm nghim cn li

    c) Tm m phng trnh c hai nghim phn bit . Khi tm h

    thc lin h gia x1v x2khng ph thuc m .

    d)Tm m phng trnh c hiu hai nghim bng 2 .e) Tm m phng trnh c hai nghim x1v x2tho mn: x1

    2+ x22

    = 8

    f) Tm gi tr nh nht ca A = x12+ x2

    2

    Bi 8:

    Tm m phng trnh: c ba nghim x1, x2,

    x3, tho mn2 2 2

    1 2 3x x x nh nht.

    Bi 9: Gii cc phng trnh sau:a) 2 4 1x x

    b) 4 1 2 5x x

    c) 01152 xx

    d) 243 xx

    e) 23 5 2 3x x x

    f)

    2 1

    2

    xx

    x

    g) 5x+2 + 3x- 4 = 4x+5

    h) 2 2 2 1 5x x

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    Bi 10:Gii cc phng trnh sau:

    a) 25 x x 1

    b) 2 9 1 2x x x

    c) 2 2 4 2x x x

    d) 3x +1 x 4 1

    e) 9 5 2x x 4

    f) 1 x 6- x -5- 2x

    g) 2 24 2 8 12 6x x x x

    h) 2x + 9- x = -x +9x +9

    Bi11: Gii cc phng trnh sau:

    a) 225 1x x

    b) 916- x x 7

    c) 5x+ 7- 3x+1= x+ 3

    d) 24 1 3 5 2 6x x x x

    e) 22 4 6 11x x x x

    f) 11 11 4x x x x

    g) 2 x 2 2 x 1 x 1 4

    k) 22 7 2 1 8 7 1x x x x x

    h)

    2 2

    2x + 8x +6 + x -1 = 2(x +1)

    Bi 12:Gii cc phng trnh sau:

    a) 2 2x -3x +3+ x -3x +6 =3

    b) 2 2 2x +x +7 + x +x +2 = 3x +3x +19

    c) 22x +3 + x +1=3x -16+ 2 2x +5x +3

    d) 22 1 3 1 0x x x

    III. Hphng trnh.Bi 1:Gii cc hphng trnh sau:

    a)3 4 2

    5 3 4

    x y

    x y

    b)4 5 3

    7 3 8

    x y

    x y

    c)

    2 3 2 4

    4 9 2

    8 4

    x y z

    y z

    y z

    d)3 2 2

    5 3 2 10

    2 2 3 9

    x y z

    x y z

    x y z

    e)

    6

    7

    11

    x y z

    xy yz xz

    xy yz zx

    f)

    2 2 18

    . 1 . . 1 72

    x x y y

    x x y y

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    Bi 2: Gii cc hphng trnh sau:

    a)2 2

    2 7 0

    2 2 4 0

    x y

    y x x y

    b)

    2 2

    2 2 2 1 0

    3 32 5 0

    x y x y

    x y

    c)

    2 2x +y +xy =7

    x+y+xy=5

    d)

    2 2x + y + xy = 4

    x + y + x y = 2

    e)

    3 3 3 3x +y +x y =17

    x+y+xy=5

    f)

    4 4 2 2

    2 2

    x +y +x y = 21

    x +y + xy =7

    Bi 3: Gii cc hphng trnh sau:

    a)

    2

    2

    x =3x-4y

    y =3y-4x

    b)

    2

    2

    x =3x+2y

    y =3y+2x

    c)

    2 2

    2 2

    x - 2y = 2x + y

    y - 2x = 2y + x

    d)

    1 32x + =

    y x

    1 32y + =

    x y

    Bi 4:Gii cc phng trnh sau:

    a) 2x - 2 x + 2 = -2x + 2 +2 x - 4

    b) x + 1+ 4- x + x +1 4 - x =5

    c) 3 312 14 2x x

    d) 3 3 32 3 2 1x x x

    e) 4 456 41 5x x

    Bi 5:Gii cc pt trnh sau:

    a) 3 x-2 + x+1= 3

    b) (A-2009 ): 2 3 3x -2 +3 6-5x -8 = 0

    c) x+ 2 217 x x 17 x 9

    d) 2 2 2 23 7 3 2 3 5 1 3 4x x x x x x x (Lin hp: x = 2)

    e) 3x +1 x 4 1( Lin hp: x =5)

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    f) 3 3 2x -1 x ( Lin hp: x = 2)

    g)1

    4 1 3 2 ( 3)5

    x x x ( lin hp: x= 2)

    h)

    3 2 2 2 6x x x ( Lin hp: x = 3; x =

    11 3 5

    2

    )

    k)23 1 6 3 14 8 0x x x x

    Bi6: Gii h phng trnh:

    /a)

    2

    2 2 9

    4 6

    x x x y

    x x y

    b)

    2

    2

    1 4

    1 2

    x y x y y

    x x y y

    c)2 2

    2 2

    3 4 1

    3 2 9 8 3

    x y x y

    x y x y

    d)3 3 3

    2 2

    1 19

    6

    x y x

    y xy x

    f) 2 2 21 7

    1 13

    xy x y

    x y xy y

    g)

    2

    2

    1 3 0

    51 0

    x x y

    x yx

    ...

    h)

    2 3 2

    4 2

    5x y x y xy xy

    4

    5x y xy 1 2x

    4

    g)

    3 3 3

    2 2

    y x 9 x

    x y y 6x

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    e)

    2 2 2 2

    11 5

    11 49

    x yxy

    x yx y

    IV. Bt phng trnh, hbt phng trnhBi 1:Tm iu kin ri suy ra tp xc nh ca cc btphng trnh sau:

    a)

    2

    1 12

    x 3x 1

    b) x 5 1 3 2x c)

    2

    2

    x 12x 3 0

    x 2

    d)

    2

    x 1x 1

    x 2

    e)x 1

    x 3 x 3

    f)1

    3 x 1 2xx 2

    g)

    x 1 1 1

    x 2 x 3 x 4x 1

    h) 232

    1 x2x 1

    x 3x 2

    Bi 2:Gii cc bt phng trnh sau:

    a) x 3

    2 x 1 x 33

    b) x 7 x 6 x 1 x 2 x

    c) x 2 . x 3. x 4 0

    d) 2

    x 1 x 2 0

    e) x 2 x 3 x 4 0

    f) 1 x 3 2 1 x 5 1 x 3

    g) x 4 x 5

    2x 5

    Bi 3:Gii cc hbt phng trnh sau v biu din tp nghim trn trc s:

    a)

    33x x 2

    5

    6x 32x 1

    2

    b)

    4x 5x 3

    6

    7x 42x 3

    3

    c)

    3 2x 732x

    5 3

    5 3x 11

    x2 2

    d)

    3x 1 3 x x 1 2x 1

    2 3 4 3

    2x 1 43 x

    5 3

    Bi 4:Gii v bin lun btphng trnhsau theo m:

    a) 2mx m 2x 4

    b) x 1 m x 2

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    Bi 5:Tm m hbt phng trnh sau c nghim:2x 4m 2mx 1

    3x 2 2x 1

    HD: Nu m x 1 2m => hc nghim khi -3 < 1+ 2m hay m > -2. Kt hp vi km -2 < m 0.x 0 lun ng=> hlun c nghim x > - 3Nu m > 1/2 th (1) => x 1 2m => hlun c nghim x 1 2m .Vy hc nghim khi m > -2

    Bi 6:Tm m hbt phng trnh sau v nghim:2mx 9 3x m

    4x 1 x 6

    .n: 2 m 3

    Bi 7: Xt du cc biu thc sau bng cch lp bng:

    a) f (x) 3x 1 x 2 x 4

    b)

    2x 1

    f(x) x 1 x 3

    c)1 1

    f(x)3 x 3 x

    d)2

    2

    x 6x 8f(x)

    x 8x 9

    e)

    2x 1f(x)

    x 1 x 3

    f)2

    4 2

    x 4x 4f(x)

    x 2x

    Bi 8:Gii cc bt phng trnh sau:

    a) 1 2x x 2 x 4 0

    b) 2 13 x

    c) 4x 1 33x 1

    d)2

    2

    x x 31

    x 4

    e)1 1 1

    x 1 x 2 x 2

    f) x 2 2x 1 x 1

    A. BT PHNG TRNH CHA N TRONG DU TRTUYT I

    L thuyt:Dng cbn:

    2 2

    f (x) a1) f (x) a a f (x) a

    f (x) a

    f (x) 0

    f (x) af (x) a2) f (x) a hoc f (x) af (x) a f (x) 0

    f (x) a

    3) f (x) g(x) f (x) g (x)

    Bi 9:Gii cc bt phng trnh sau:

    a) 3x 5 2 e)2 x

    2x 1

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    b) 5 8x 11

    c) x 2 2x 3

    d) x 1 x x 2

    f)x 1

    2x 1

    h)x 1

    1x 2

    Bi 10: Gii cc bt phng trnh sau:

    a) 2 x 1 x 4 b) x 1 2 x 1

    c)x 3 x

    1x 2

    d)2

    3x1

    x 4

    e)2

    x 6 x 5x 9 f) 2x 2x 3 3x 3

    g) 2x x 5 0

    h) 2x 6x 7 x 6

    k)2

    2

    x 3x 13

    x x 1

    * Bi luyn tp:Gii cc bt phng trnh sau:

    2

    2

    2

    2 2

    2

    2 2

    1) 6 ( 6 1 7)

    2) 5 6 ( 1 2 3 6)

    3) 5 4 2 ( 2 2 4)

    1 14) 3 2 1 ( )

    4 2

    5) 5 9 6 (1 3)

    6) 2 4 0 ( 2 1)1

    7) 1 2 ( )2

    8) 1 2 3 ( 0 2)

    29) 3 5 3 ( )

    3

    x x x x

    x x x x

    x x x x x

    x x x x x

    x x x x

    x x x x x

    x x x

    x x x x x

    x x x x

    2

    2

    2

    1) 2 4 2 , ( 3 5)

    4 22) 1 , ( )

    2 5

    2 53) 1 0 (3 2)

    3

    2 104) 3 (3 )

    5 6 3

    26) 2 (0 1)

    2 3 3 1 1 39) 1 ( )

    1 4 2 4 2

    x x x x x

    x xx

    x x

    xx

    x

    xx

    x x

    x xx

    x

    xx x

    x

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    B. BT PHNG TRNH CHA N TRONG DU CN

    L thuyt:Dng cbn:

    2

    2

    f (x) 0 f (x) 0f (x) 0

    1) f (x) g(x) g(x) 0 ; 2) f (x) g(x) g(x) 0f(x) g(x)

    f(x) g(x) f(x) g (x)

    g(x) 0g(x) 0

    f (x) 0f (x) 0

    3) f (x) g(x) g(x) 0g(x) 0

    f (x) 0

    f(x) g (x)

    2f(x) g (x)

    B

    11: Gii cc bt phng trnh sau:

    a) 2x 3x 5 x 1

    b) 2x 2x 1 x

    c) 2 4 5 2 3 x x x

    d) 22x 6x 1 x 2 0 e) 3x < 2x

    f) 7 1 3 18 2 7 x x x g) 2 21 1 3 x x

    Bi 12: Gii cc bt phng trnh sau:

    a) 262 xxx ( 3x )

    b) 1)1(2 2 xx ( 311 xx )

    c) xxx 122 ( 4x )

    e) xxx 2652 2 ( 110 xx )

    f) 12411 xxx ( 54 x )

    g) 1553 xx ( 4x )

    h) xxx 12 (3

    323 x )

    k)3

    73

    3

    )16(2 2

    x

    xx

    x

    x

    * Bi luyn tp:Gii cc bt phng trnh sau:

    1x

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    2

    2

    1) 7 6 3 2 (1 6)

    12) 4 1 ( 4 0 )

    6

    73) ( 1)(4 ) 2 ( 1 )

    2

    x x x x

    x x x x x

    x x x x x

    4) xxx 31415 ( 1

    4x )

    5) 5 1 1 2 4 ( 10 2) x x x x x

    6) 2 35 4 3 ( 3 4 )3

    x x x x x

    7)2 22 5 4 2 4 3

    ( 1; 1 2 6; 1 2 6; 1)

    x x x x

    x x x x

    8) 2 22 4 3 3 2 1 ( 3; 1) x x x x x x

    9) xxxx 271105 22 ( 13 xx )

    10) 2855)4)(1( 2 xxxx (9< x< 4)

    11)2 2 23 2 4 3 2 5 4x x x x x x

    ( 4x V x =1)12) 2 2x 2 x 3x 4 x 4 x 2 4 x 8

    13)21 1 4 2 1 1

    3 ( ; ;04 2 2

    xx x x

    x

    15)23x 16x 5 1

    2 x 1 3 x 5x 1 3

    16) 1 8x 3

    4 x4x

    Bi7Gii cc BPT sau:

    a) 25

    2 3 5 1 32

    x x x x

    b) 2 2 1 2x x x x

    c) 2 23 3

    1 3 1 1 ; 12 2

    x x x x

    d) x + 2 - x - 6 > 2 ( x 6 7)

    e) 2 3 42x +1 x x - 3 x

    f) x +3 - x -1 x - 2 2 213

    x

    ; x 1 2 x 2 5x 1 2 x 3

    g) (x+2) x x x 2 23 4 4; ( 2;4 8x x ) HD : x 2 x 2 0 ...

    h)21 1 4 1 1

    3 ; 02 2

    xx x

    x

    HD: lin hp: 22

    04

    3; 04 3. 1 1 41 1 4

    xx

    xx xx

    k) 2 2 23 2 4 3 2 5 4 4; 1x x x x x x x x

    m) 5 2 3 3 0 4; 1x x x x x x

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    n) 2 21

    4 3 2 3 1 1 1;2

    x x x x x x x

    HD: phn tch thnh tch

    i) 224 4 2 2 2 3 2 3 x x x x x x

    HD:

    2 2 2 3 2 24 4 4 2 0 dat: t = 4 >0 ta co: -t -t +20 t>x x x x x x x x t t t

    j) 2 2x 25

    x 4 8 x x HD:dat t= x 4,t 0 t x 4 taco: t 2 2 4 t4 4

    2 32t t 6 0 t2

    ...

    p) (A-2010):

    x x

    x x21

    1 2 1

    . HD: ta c:

    x x x

    2

    2 1 3 32 1 22 2 2

    MS 0

    Do vi x 0 BPT tng ng vi: x x x x22 1 1 . Thy x = 0 khng l nghim

    ca BPT

    Nn x>0. Chia c2 vcho x >0 ta c: x xx x

    1 12 1 1

    .

    t t = x x txx2

    1 12 ta c:

    tt t t

    t t2

    2

    12 1 1 1

    2 1 0

    x x x x xx

    1 1 5 3 51 1 0

    2 2

    C). BI TP NGH

    Bi 5:Gii v bin lun cc bt phng trnh sau:

    1) mx2 x

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    2) 3x2 2 < xm

    3) mx m2x > m3x

    III. PHNG PHP HM S

    Phng php ny da vo vic kho st mt vi tnh cht c bit no ca hm sdn n kt lun nghim cho phng trnh, bt phng trnh ang xt.

    V d: Gii bt phng trnh: 9 2 4 5x x .

    Gii:

    Xt hm s 9 2 4y x x , ta thy ngay hm sny ng bin trn tp xc nh 2x .Tc f(0) = 5 do :

    + Vi x > 0 th f(x) > f(0) = 5 nn x > 0 l nghim.

    + Vi 2 0 ( ) (0) 5x f x f nn 2 0x khng l nghim.Tm li: x>0 l nghim.

    IV. P DNG BT NG THC

    1). MT SV D

    V d1:Tm gi trln nht ca hm s 2 4y x x v p dng gii phng trnh:22 4 6 11x x x x .

    Gii:p dng bt ng thc : 2 2 22( ) ( )a b a b .ta c:

    2

    2( 2 4 ) 2 4 2x x x x y . Do y ln nht bng 2 khi v chkhi:

    2 4 3x x x .Mt khc 2 26 11 ( 3) 2 2.x x x x nn:

    2

    2

    2 4 22 4 6 11 3

    6 11 2

    x xx x x x x

    x x

    V d2:Gii phng trnh

    x3 +x

    1= 4 8 x (1)

    Gii.

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    MX: x > 0

    C4

    x

    1x3

    =8

    x

    1

    x

    1xxxxxx

    8 x (2) x > 0 (BT Csi)

    Vy (1) du = (2) xy ra x =x

    1 x = 1.

    V d3:Gii phng trnh

    2x + x4 = 2x 6x + 11. (1)

    Gii.

    * Cch 1

    2)1(VT ( 21 + 21 )(x2 + 4x) = 4. (BT Bunhiacopxki)

    VT 2.

    VP(1) = 2)3x( + 2 2.

    Vy (1)

    2)1(VP

    2)1(VT

    03x

    1

    x4

    1

    2x

    x = 3.

    * Cch 2

    t A x 2 4 x

    2 2 2A 2 2 (x 2)(4 x) A 2 (x 2) (4 x) A 4 (BT Csi)

    VT 2 vi 2 x 4

    Du bng xy ra khi v chkhi x2 = 4x x = 3

    Mt khc VP = 2 2x 6x 11 (x 3) 2 2 , du bng xy ra khi v chkhi x = 3

    Suy ra phng trnh cho tng ng vi h2

    x 2 4 x 2x 3

    x 6x 11 2

    Vy x = 3 l nghim duy nht ca phng trnh

    V d4:Gii phng trnh

    3x7x3 2 + 4x3x2 = 2x 2 + 1x5x3 2 (1)

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    n tp ton 10 phn i s (lp 10C3)

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    Gii.

    Vit 3x7x3 2 = )2x(21x5x3 2

    4x3x2 = )2x(32x 2

    Vy (1)

    01x5x3

    02x02x

    2

    2 x = 2.

    V d5:Gii phng trnh

    2 2 23x 6x 7 5x 10x 14 4 2x x (1)

    Gii.

    2 2 2(1) 3(x 1) 4 5(x 1) 9 5 (x 1)

    VT(1) 5, VP(1) 5, x

    VT(1) 5(1) x 1 0 x 1

    VP(1) 5

    Vy x = -1 l nghim duy nht ca phng trnh

    V. GII BT PHNG TRNH BNG CCH NHN LNG LIN HP

    MT SV D:

    V d1:Gii bt phng trnh

    21 1 4x3

    x

    Bng cch nhn lng lin hp bt phng trnh tng ng

    2

    2

    2 2

    4x3

    x 1 1 4x

    x 0 x 0

    4x 3 3 1 4x 3 1 4x 4x 3

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    n tp ton 10 phn i s (lp 10C3)

    GV son: PhmTun Khng Trang

    21 4x c ngha th1 1

    x2 2

    . V x 1

    24x3< 0

    Do (1),(2)x 0

    1 1x

    2 2

    . Tp nghim 1 1

    S ; \ 02 2

    V d2:Gii bt phng trnh

    2

    12x 82x 4 2 2 x

    9x 16

    (1)

    Bng cch nhn lng lin hp bt phng trnh tng ng

    22

    6x 4 2(6x 4)(3x 2) 9x 16 2 2x 4 2 2 x 0

    2x 4 2 2 x 9x 16

    (2)

    Li thc hin php nhn lin hp

    2 2

    2 2

    2 2

    (2) (3x 2) 9x 16 4 12 2x 4 8 2x 0

    (3x 2) 9x 8x 32 16 8 2x 0

    (3x 2) x 2 8 2x x 2 8 2x 0 (3)

    28 2x c ngha th -2 x 2. Do 2x 2 8 x 2 8 2x 0 nn

    2

    2 2

    (3) (3x 2) x 2 8 2x 0

    3x 2 0 3x 2 0 (I) (II)

    x 2 8 2x 0 x 2 8 2x 0

    Gii (I)4 2

    x 23

    Gii (II) 2 2 2

    2x 0 0 x< 2 2

    2 x 0 0 x< 2 x

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    n tp ton 10 phn i s (lp 10C3)

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    V. Tslng gic ca cung lng gic

    A- L thuyt.1. Cng thc lng gic c bn.

    sin k2 sin

    cos( k2 ) costan k tan

    cot k cot

    2 2sin cos 1

    sintan , kcos 2

    coscot , k

    sin

    2

    2

    2

    2

    11 tan

    cos

    1 1 cotsin

    1cot , k

    tan 2

    2.Gi trlng gic ca cc gc (cung) c lin quan c bit.

    sin(- ) = sin

    cos(- )= - cos

    tan tancot cot

    cos2

    sin

    sin2

    cos

    tan cot2

    cot tan2

    sin(- ) = - sin

    cos(- ) = cos

    tan(-

    ) = - tan

    cot(- ) = - cot

    sin(+ ) = - sin

    cos(+ )= - cos

    tan tancot cot

    3. Mt scng thc lng gic thng gp.

    a) Cng thc cng.

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    n tp ton 10 phn i s (lp 10C3)

    GV son: PhmTun Khng Trang

    cos( ) cos .cos -sin .sin

    cos( ) cos .cos sin .sin

    sin( ) sin .cos cos .sin

    sin( ) sin .cos cos .sin

    tan tantan( )

    1 tan tan

    tan tantan( )

    1 tan tan

    b) Cng thc nhn i.

    2 2 2 2

    2

    sin2 2sin .cos

    cos2 cos sin 2cos 1 1 2sin

    2tantan2

    1 tan

    c) Cng thc hbc.

    2 21 cos2 1 cos2sin ; cos2 2

    d) Cng thc bin i tch thnh tng.

    1cos .cos cos cos

    2

    1sin .sin cos cos

    2

    1sin .cos sin sin

    2

    e) Cng thc bin i tng thnh tch.

    cos cos 2cos cos2 2

    cos cos 2sin sin2 2

    sin sin 2sin cos

    2 2sin sin 2cos cos

    2 2

    4. Bng gi trlng gic ca cc cung c bit.

    Gc

    00 300 450 600 900 1200 1350 1500 1800

    06

    4

    3

    2

    2

    3

    3

    4

    5

    6

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    n tp ton 10 phn i s (lp 10C3)

    GV son: PhmTun Khng Trang

    sin 01

    2 2

    2

    3

    2 1

    3

    2

    2

    2

    1

    2 0

    cos 1 3

    2

    2

    2

    1

    2 0

    1

    2

    2

    2

    3

    2 -1

    tan 01

    3

    1 3 kx - 3 -1 1

    3

    0

    cot kx 3 11

    3 0

    1

    3 -1 3 kx

    * Ch :

    cos 0 khi im ngn ca cung thuc gc phn tthI v IVcos 0 khi im ngn ca cung thuc gc phn tthII v IIIsin 0 khi im ngn ca cung thuc gc phn tthI v IIsin 0 khi im ngn ca cung thuc gc phn tthIII v IV

    B- Cc bi tp p dng.

    Bi 1:Tnh cc gi trlng gic ca gc bit.a) sin=

    2 3v