方程(2k-1)x+3k-2=0
(2k-1)x+3k-2=0
===> (2k-1)x=2-3k
===> 当2k-1≠0,即k≠1/2时:x=(2-3k)/(2k-1)
已知x不在区间[-1,1]内
则:
①x=(2-3k)/(2k-1)>1
===> (2-3k)/(2k-1)-1>0
===> [(2-3k)-(2k-1)]/(2k-1)>0
===> (3-5k)/(2k-1)>0
===> (5k-3)/(2k-1)<0
(5k-3)*(2k-1)<0
===> 1/2<k<3/5
②x=(2-3k)/(2k-1)<-1
===> (2-3k)/(2k-1)+1<0
===> [(2-3k)+(2k-1)]/(...全部
(2k-1)x+3k-2=0
===> (2k-1)x=2-3k
===> 当2k-1≠0,即k≠1/2时:x=(2-3k)/(2k-1)
已知x不在区间[-1,1]内
则:
①x=(2-3k)/(2k-1)>1
===> (2-3k)/(2k-1)-1>0
===> [(2-3k)-(2k-1)]/(2k-1)>0
===> (3-5k)/(2k-1)>0
===> (5k-3)/(2k-1)<0
(5k-3)*(2k-1)<0
===> 1/2<k<3/5
②x=(2-3k)/(2k-1)<-1
===> (2-3k)/(2k-1)+1<0
===> [(2-3k)+(2k-1)]/(2k-1)<0
===> (1-k)/(2k-1)<0
===> (k-1)/(2k-1)>0
(k-1)*(2k-1)>0
===> k>1,或者k<1/2
综上有:k∈(-∞,1/2)∪(1/2,3/5)∪(1,+∞)。
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