英语填空(②为平方)1.若关于X的一元二次方程X②-X+a-4=0的一根大于0,另一根小于0,求实数a的取值范围.英语1.The person___ ____.I spoke just now is the manager that I told you about2.The pencil ____ _____ he was writ
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英语填空(②为平方)1.若关于X的一元二次方程X②-X+a-4=0的一根大于0,另一根小于0,求实数a的取值范围.英语1.The person___ ____.I spoke just now is the manager that I told you about2.The pencil ____ _____ he was writ
英语填空
(②为平方)
1.若关于X的一元二次方程X②-X+a-4=0的一根大于0,另一根小于0,求实数a的取值范围.
英语
1.The person___ ____.I spoke just now is the manager that I told you about
2.The pencil ____ _____ he was writing broke.
3.Wu Dong ___ ___ t weng to the concert,enjoyed it very much.
4.The teo things ____ ____ Marx was not sure were the grammar and sone of the idinms of english.
5.Her bag ____ ____she put sll her books,has not been found.
6.The stories about the long March ______ _______ this is one example ,are well written.
英语填空(②为平方)1.若关于X的一元二次方程X②-X+a-4=0的一根大于0,另一根小于0,求实数a的取值范围.英语1.The person___ ____.I spoke just now is the manager that I told you about2.The pencil ____ _____ he was writ
数学:
1.x1*x2=a-4
首先有两个根,验证delta,1的平方-4乘以1乘以(a-4)要大于零
然后根式一正一负,就用韦达定理,1乘以(a-4)要小于零。 a<4
英语我也不晓得你啥子要求,就给你做数学好了。
愧疚。。。
根据韦达定理 x1x2=a-4<0 a<4
英语不好..
....上面的过程够充分了
韦达定理 x1x2=a-4
两个根一个<0 一个>0 所以乘积<0
所以有x1x2<0 即a-4<0 a<4
1.若关于X的一元二次方程X②-X+a-4=0的一根大于0,另一根小于0,求实数a的取值范围。
△=1-4a+16>0 a<-15/4
x1x2=a-4<0 a<4
所以a<-15/4