:
- ;
- , ;
- , .
.
ax2+bx+c>0, ax2+bx+c<0,
ax2+bx+c≤0, ax2+bx+c≥0, 0.
ax2+bx+c=0 , , ax2+bx+c =a(x-x )(x-x ), :
ab>0 ab<0
:
-22-5+3>0, 22+5-3<0, 22+5-3=0, x1,2 = x1= , x2= -3; 22+5-3=2(x- )(x+3); : (-3; ) | 2(x- )(x+3)<0, . |
. =ax2+bx+c, a 0. , .
.
D | a>0 | a<0 |
D<0 | ||
D=0 | 1,2= | 1,2= |
D>0 | 1,2= | 1,2= |
:
-22-5+3>0,
1.
2. , ,
3. , ,
4. , ,
5. ,
22+5-3=0
x1,2 =
x1= , x2= -3;
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: (-3; )
.
1. :
) (-2)(+4)>0, ) x2-3x+2<0,
) (x-3)(x+5)<0, ) x2-2x-3>0.
2. ( ):
) 2 5 > 0, ) 4 ≤ -2 ) 2+2-15>0.
) 2 > 25, ) 1/32 > 1/9
) 2 36 < 0, )
) 32 + + 2 > 0, )
3. 2 + 7 ≤ 30.
4. 3 2 > -40.
|
|
5. , :
) )
) )
6. :
) 15 2 + 10 ≥ 0, ) 2 + 5 8 < 0.
7. 32 2 + 6 = 0
) 2 ; ) 1 ; ) .
.
: , .
:
(2 )( + 3) ≥ 0, (1 ) ( + 4) > 0,
42 + 4 + 1 ≤ 0, 92 + 6 + 1 > 0,
2 1 ≥ 0, 3 -2 1 ≥ 0,