.
: .
. , , .
Û
, . . .
, ¹ 0. : , .
.
, . :
) :
;
) n - :
;
) , ,
f(x) = g(x);
) , . .
.
.
.
x2 - 3 = 1;
-3 .
x2 = 4;
-2 2.
, x .
.
x1 = -2 - :
x2 = -2 - .
, -2 2.
. .
, .
. , :
) x - 9 0;
x 9;
) 1 - x 0;
-x -1;
x 1.
: x .
: .
:
.
, , , . .
> 1.
, :
x < -1.
: x >1 x < -1.
: (1)..
. 3 > 9.
3 x > 3 (2). , (1) (2). .(1) (2).
M = (- ; 8) (8; + )- (1).
B = (3; + ) - (2).
|
|
(1)
A = B M =((- ; 8) (8; + ) (3; + ) = (3; 8) (8; + ),
: x (3; 8) (8; + ).
: .
.
: x [-1; 5) (5; + )
0 x = -1, . ( , .. ), :
(-1; 5) 0, 8,
0 8 , , .
: (-5; + ).
:
.
, : x (0; 1) (1; 7) (7; + )
x = 1.
(0;1) 0,5;
(1; 7) 4,
(7; + ) 9,
.
, (0; 1) (1; 7)
: (2x - 6)(3x + 12)(5x + 1)<0.
.
: - 4; - 0,2; 3.
, c "+" "-"....
x (- ; -4) (-0,2; 3).
: 7 - x. . t = , t 0, ( )
t2 = x + 5; x = t2 - 5 t 7 - t2 + 5;
t2 + t - 12 0;
: t R.
t2 + t - 12 = 0;
t1 = -4; t2 = 3.
f(t) = t2 + t - 12; . , , f(x) = (x - 3)(x + 4).
f(4) =4 2 + 4 - 12 = 8 >0;
, f(t) = t2 + t - 12 0, -4 t 3. t 0, 0 t 4. x,
0 3. , 0 x + 5 9, -5 x 4 , ,
x [-5; 3].
: x [-5; 3].
: 2x2 - 8x + 6 > .
.
2 3(x2 - 4x + 3) > .
t = , t > 0 2t2 > t; 2t2 - t > 0; t(2t -1) > 0.
, 1, 0 0,5. :
2t2 > t t > 0,5.
.
> 0,5, x < 1 x > 3.
x2 - 4x + 3 > 0,25;
4x2 - 16x + 11 > 0;
D/4 = 64 - 44 = 20, D > 0.
x1 = , x2 =
, 0,5 < < 1 3 < < 3,5.
x (- ; ) (; + ).
: (- ; ) (; + ).
: 2sin2x - 3sinx - 2 < 0.
.
sinx = t, t [-1; 1] (1),
2t2 - 3t - 2 < 0.
.
|
|
1) Ÿ 2.
2) D = 32 - 4 2(-2) = 9 + 16 = 25, , D > 0.
3) t1 = -0,5; t2 = 2,
t (- ; - 0,5) (2; + ) (2).
(1) (2) [-1; -0,5).
, .
-1 sinx < -0,5. y = sinx.
<="" p="">
x (- + 2 k; - + 2 k), k Z.
: x (- + 2 k; - + 2 k), k Z.
: 3 > lg() + 2.
.
- > 0 x < 0 = |x|, |x| = -x , , x < 0, 3 > lg(-x) + 2. t = , t2 - 3t + 4 < 0.
1) .
2) : t1 = 1, t2 = 2.
3) 1 < t < 2.
1 < < 2. , .
1 < lg(-x) < 4;
-1000 < x < -10.
: (-10000; -10).