设二次方程anx^2-a(n+1)x+1=0有两个根x1,x2,且满足6x1-2x1x2+6x2=3.且a1=1
设二次方程anx²-a(n+1)x+1=0(n=1,2,3…)有两根α和β,且满足6α-2αβ+6β=3。,a1=1
(1)试用an表示a(n+1);
(2)求证:{an-2/3}是等比数列;
(3)求数列{an}的通项公式。
人气:433 ℃ 时间:2020-04-16 10:26:14
解答
6α-2αβ+6β=36(α+β)-2αβ=36a(n+1)/an -2/an=3a(n+1)=(1/2)an+(1/3)a(n+1)-(2/3)=(1/2)an+(1/3)-(2/3)=(1/2)[an-(2/3)]所以:{an-2/3}是公比为1/2的等比数列设bn=an-(2/3)则:b1=a1-(2/3)=1/3bn=b1*(1/2)^(n-1...
推荐
- 设二次方程anx^2-a(n+1)x+1=0有两个根x1,x2,且满足6x1-2x1x2+6x2=3.已知a1=7/6.
- 设二次方程anx^2-a(n+1)x+1=0有两个根x1,x2,且满足6x1-2x1x2+6x2=3
- 设数列(an),a1=5/6,若以a1,a2,.,an为系数的二次方程:a(n-1)X2-anX+1=0,都有根A、B满足3A-AB+3B=1
- (1/2)设二元一次方程anx^2-an+1x+1=0.有两根x1.x2、满足6x1-2x1x2+6x2=3、且a1=7/6、 用an表示an+
- 方程anx²-an+1x+1=0有两个实数根x1,x2,满足6x1-2x1x2+6x2=3,a1=7/6,则an=求的是an
- I can't always understand when people talk to me中talk为什么不用过去式
- 7/1+4/1+25/12等于多少
- 考大家一道初一的数学题(迎接令一个挑战)
猜你喜欢