Question

Решите неравенства 1-3.

Answer 1

1. Х'2+2х-3<=0
D=4-4*3*1=16
X1x2=(-2+-4)/2
X1=1
X2=-3
2.x'2-6x>o
D=36
X1x2=(6+-6)/2
X1=6
X2=0
3.x'2-9>=0
D=36
X1x2=(0+-6)/2
X1=3
X2=-3

Answer 2

1)x²+2x-3≤0
x²+3x-x-3≤0
x(x+3)-(x+3)≤0
(x+3)(x-1)≤0

+++[-3]-----[1]+++
x∈[-3;1]

2)x²-6x>0
x(x-6)>0

++++(0)-----(6)+++
x∈(-∞;0)U(6;+∞)

3)x²-9≥0
(x-3)(x+3)≥0

+++[-3]-----[3]++++
x∈(-∞;-3]U[3;+∞)