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Chuyen e12: CAC BAI TOAN LIEN QUAN EN THAM SOCac phng phap giai thng s dung

Phng phap 1: Phng phap ai so. S dung cac phep bien oi tng ng thch hp e tm so nghiem

V du: Tm m e he phng trnh sau co nghiem:

=+

=+

myyxx

yx

31

1

Phng phap 2: Phng phap giai tch S dung cong cu ao ham xet tnh n ieu, cc tr, GTLN & GTNN e tm so

nghiem

V du: Tm m e vi moi034cossin82cos2 + mxxx

4;0

x

Phng phap 3: Phng phap o th cua giai tch Da vao v tr tng oi cua cac o th e e tm so nghiem

V du: Bien luan theo m so nghiem cua phng trnh: mxxxx +=+ 5452 22

Phng phap 4: Phng phap o th cua hnh hoc giai tch Da vao cac o th cua hnh hoc giai tch e tm so nghiem

V du: Bien luan theo m so nghiem cua phng trnh: mxx = 2312 Phng phap 5: Phng phap ieu kien can va u

V du: Cho he phng trnh:

=+

=+222 6 myx

myx

Tm m e he phng trnh a cho co nghiem duy nhat, xac nh nghiem o

Chu y: Khi co s dung an phu th phai tm ieu kien ung cho an phu

80

Phng phap ai so Phng phap giai tch Phng phap o th cua

giai tch

Pt,bpt,hpt, hbptco cha tham so

Phng phap o th cuahnh hoc giai tch

Phng phap ieu kiencan va u

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BAI TAP REN LUYEN:

Bai 1: Tm m e cos vi moi034cossin822 + mxxx

4;0

x

Bai 2: Tm m e phng trnh sau co nghiem:

02sin4

12coscossin 244 =+++ mxxxx

Bai 3: nh m e phng trnh : mxxgxtgxxx =++++++ )cos1sin1cot(211cossin

co nghiem

2;0

x

Bai 4: Cho bat phng trnh : (1)0324 + mm xx

Tm m e bat phng trnh (1) co nghiem.

Bai 5: Cho phng trnh : ( ) 0loglog42

1

2

2 =+ mxx (1)

Tm m e phng trnh (1) co nghiem thuoc khoang (0;1).

Bai 6: Cho ham so: 1)coscos2

()coscos

4

(2

2

2=++

xxmxx

Tm m e phng trnh co nghiem thuoc ).2

;0(

Bai 7: Tm tat ca cac gia tr cua m sao cho ta co:Rxmxxxx ++ ,cos.sincossin 66

Bai 8: Tm m e bat phng trnh sau ung vi moi x [ 4;6] 2(4 x)(6 x) x 2x m+ +

Bai 9: Cho phng trnh : 01)cot(3sin

3 22

=+++ gxtgxmxtgx

Tm tat ca cac gia tr cua m e phng trnh co nghiem.Bai 10: Xac nh m e phng trnh :

4 42(sin x cos x) cos4x 2sin2x m 0+ + + =

co t nhat mot nghiem thuoc oan [0; ]2

Bai 11: Cho phng trnh : mxxx = )sin(cos42sin (1)Tm tat ca cac gia tr cua m e phng trnh (1) co nghiem.

Bai 12: Cho bat phng trnh : 2m. 2x 7 x m+ < + (1)Tm m e bat phng trnh nghiem ung vi moi x .

Bai 13: Tm m e phng trnh : 4 4 6 6 24(sin x cos x) 4(sin x cos x) sin 4x m+ + = co nghiem.Bai 14: Tm tat ca cac gia tr cua tham so m e phng trnh: mm xxxx 2)22)(1(44 2211 ++=+ ++

co nghiem thuoc oan [0;1].

Bai 15:Cho phng trnh : 032)2(2 22 =+ mxxxx Vi gia tr nao cua m th phng trnh co nghiem.

Bai 16: Cho phng trnh cos4 6sin cos 0x x x m+ =

81

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nh m e phng trnh co nghiem 0;4

x

.

Bai 17: Cho ham so 2 3f(x) sin 2x 2(sin x cosx) 3sin 2x m= + + +

Tm m e f(x) 1 vi moi x [0; ]2

Bai 18: Tm m e phng trnh : 0)cos)(sincos.(sin2cos2 =++ xxmxxx co nghiem tren oan

2;0

Bai 19: Cho phng trnh : 0123).2(9211211 =+++ ++ mm xx

Tm m e phng trnh co nghiem.

Bai 20: Cho bat phng trnh: 42)1( 222 ++++ xxmx (1)Tm m e co nghiem x ]1;0[

Bai 21: Tm m e phng trnh sau co hai nghiem trai dau: 013)52(9)3( =+++ mmm xx

Bai 22: Tm m e phng trnh sau co nghiem:mxxxx =+++ )6)(3(63

Bai 23: Tm m e phng trnh : 2 2 22 1 42

(log x) log x 3 m(log x 3)+ = co nghiem thuoc [32; + )

Bai 24: Cho bat phng trnh : mxxx =+++2sin

22cos1

22cos2

2

Xac nh m e bat phng trnh thoa man vi moi x

Bai 25: Cho phng trnh: 022

12

1

22 =++

m

x

x

Tm m sao cho phng trnh co nghiem duy nhat trong oan [0;1]

-------------------------------Het------------------------------

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