不等式(x^2-x+1)(x^2-x-1)>0的解集是

2024-12-20 04:28:56
推荐回答(2个)
回答1:

解:因为x^2-x+1=x^2-2*(1/2)x+1/4-1/4+1=(x-1/2)^2+3/4>0所以原不等式解集就是x^2-x-1>0的解集。x^2-x-1>0x^2-2*(1/2)*x+1/4-1/4-1>0(x-1/2)^2-(√5/2)^2>0(x-1/2+√5/2)(x-1/2-√5/2)>0x>(√5-1)/2或x<-(√5+1)/2

回答2:

因为(x^2-x+1)恒大于0,所以只需求得(x^2-x-1)>0即可。解得x>(1+√5)/2或x<-(1+√5)/2。