急~~~关于x的不等式的(a^2-11-x)/(a-x)>-4
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发布时间:2024-09-29 00:34
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热心网友
时间:2024-10-02 18:35
(a^2-11-x)/(a-x)>-4
(a^2-11-x)(a-x)>-4(a-x)^2, a不=x
(a^2-11-x)(a-x)+4(a-x)^2 > 0, a不=x
(a^2-11-x+4(a-x))(a-x) > 0, a不=x
(a^2+4a-11-5x)(a-x) > 0, a不=x
(x-(a^2+4a-11)/5)(x-a) > 0, a不=x
(a^2+4a-11)/5<a 时 , x<(a^2+4a-11)/5 或 x>a
(a^2+4a-11)/5>a 时 , x<a 或 x>(a^2+4a-11)/5
(a^2+4a-11)/5=a 时 , x不等于a
(a^2+4a-11)/5 < a --> (1-3根号5)/2 < a < (1-3根号5)/2
log2(a+1+x)>2log2(a-x)-2
log2(a+1+x)>log2(((a-x)/2)^2)
(a+1+x)>((a-x)/2)^2
4a+4+4x>a^2-2ax+x^2
x^2-(2a-4)x+(a^2-4a-4)<0
a^2-4a-4 = (a-(2+2根2))(a+(2-2根2))
(x-a+(2+2根2))(x-a-(2+2根2))<0
a-(2+2根2) < x < a+(2+2根2)
1属于B,
a-(2+2根2) < 1 < a+(2+2根2)
-1-2根2 < a < 3+2根2
2属于CRA,
(a^2+4a-11-10)(a-2) < 0
(a^2+4a-21)(a-2) < 0
(a-3)(a+7)(a-2) < 0
a>3, a>-7, a<2
或 a>3, a<-7, a>2
或 a<3, a>-7, a>2
或 a<3, a<-7, a<2
所以 2<a<3 或 a<-7
-1-2根2 < a < 3+2根2
综合 2<a<3
热心网友
时间:2024-10-02 18:35
a a a a a
热心网友
时间:2024-10-02 18:36
(a^2-11-x)(a-x)+4(a-x)^2 > 0, a不=x
(a^2-11-x+4(a-x))(a-x) > 0, a不=x
(a^2+4a-11-5x)(a-x) > 0, a不=x
(x-(a^2+4a-11)/5)(x-a) > 0, a不=x
(a^2+4a-11)/5<a 时 , x<(a^2+4a-11)/5 或 x>a
(a^2+4a-11)/5>a 时 , x<a 或 x>(a^2+4a-11)/5
(a^2+4a-11)/5=a 时 , x不等于a
(a^2+4a-11)/5 < a --> (1-3根号5)/2 < a < (1-3根号5)/2
log2(a+1+x)>2log2(a-x)-2
log2(a+1+x)>log2(((a-x)/2)^2)
(a+1+x)>((a-x)/2)^2
4a+4+4x>a^2-2ax+x^2
x^2-(2a-4)x+(a^2-4a-4)<0
a^2-4a-4 = (a-(2+2根2))(a+(2-2根2))
(x-a+(2+2根2))(x-a-(2+2根2))<0
a-(2+2根2) < x < a+(2+2根2)
1属于B,
a-(2+2根2) < 1 < a+(2+2根2)
-1-2根2 < a < 3+2根2
2属于CRA,
(a^2+4a-11-10)(a-2) < 0
(a^2+4a-21)(a-2) < 0
(a-3)(a+7)(a-2) < 0
a>3, a>-7, a<2
或 a>3, a<-7, a>2
或 a<3, a>-7, a>2
或 a<3, a<-7, a<2
所以 2<a<3 或 a<-7
-1-2根2 < a < 3+2根2
综合 2<a<3