根据韦达定理,得
lga + lgb=2
lga · lgb=1/2
∴(lg a/b)²
=(lga - lgb)²
= (lga)² + (lgb)² - 2lga·lgb
= (lga +lgb)² - 4lga·lgb
= 2² - 2
=2
若lga,lgb是方程2x^2-4x+1=0的两个根,则(lg a/b)^2的值等于
若lga,lgb是方程2x^2-4x+1=0的两个根,则(lg a/b)^2的值等于
数学人气:929 ℃时间:2020-04-04 00:37:32
优质解答
我来回答
类似推荐
猜你喜欢
- 1翻译1. Can this be important? No.This may not beimportan
- 2九年级上册语文古文题目
- 3乙酸与浓硫酸能否反应?
- 4王师傅加工20个零件,加工一个合格品可得5元,加工一个次品倒扣2元.加工完后,他领到65元工钱,求合格率?
- 5下列城市,位于长江上游又属西部地区的是( ).
- 6已知f(x)=根号内(3-ax)/(a-1)(2)若f(x)在区间(0,1】是减函数,求实数a的取值范围
- 7If you work hard ____,you won't have to sit up all night before the exam.
- 8如图,在四边形ABCD中BC=CD,点E是BC的中点,点F是CD的中点,且AE垂直BC,AF垂直CD求证AB=AD人在急!
- 9We have so much homework,it is impossible to hand it/them in tomorrow,我认为是them,
- 10《上课铃响了,我们说话更多了》关于这样的作文