英语翻译1.Let S be a set of real numbers that satisfy the following conditions:0 is in S; Whenever x is in S then 2^x+3^x is in S; whenever x^2+x^3 is in S then x is in S.Prove:S contains at least two distinct real numbers between 0 and 1.2.Suppo

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/14 10:34:05

英语翻译1.Let S be a set of real numbers that satisfy the following conditions:0 is in S; Whenever x is in S then 2^x+3^x is in S; whenever x^2+x^3 is in S then x is in S.Prove:S contains at least two distinct real numbers between 0 and 1.2.Suppo
英语翻译
1.Let S be a set of real numbers that satisfy the following conditions:
0 is in S; Whenever x is in S then 2^x+3^x is in S; whenever x^2+x^3 is in S then x is in S.
Prove:S contains at least two distinct real numbers between 0 and 1.
2.Suppose p(x) is a polynomial with integer coefficients.Show that if p(a)=1for some integer a then p(x) has at most two integer roots(that is,there are at most two integers b and c such that p(b)=0 and p(c)=0.)
1.S为实数集合并有以下性质
0为S中的一个元素;
若x在S中,那么2^x+3^x也在S中;
若x^2+x^3在S中,那么x也在S中。
证明:S至少含有2个介于0和1之间的不同的实数元素。
2.假设p(x)是整系数多项式。证明若对于整数a,p(a)=1,则p(x)至多含有两个整数根。(即至多存在两个整数b,c 使p(b)=p(c)=0)

英语翻译1.Let S be a set of real numbers that satisfy the following conditions:0 is in S; Whenever x is in S then 2^x+3^x is in S; whenever x^2+x^3 is in S then x is in S.Prove:S contains at least two distinct real numbers between 0 and 1.2.Suppo
1、设 S 是实数构成的集合,满足以下条件:
(1)0∈S ;
(2)如果 x∈S ,那么 2^x+3^x ∈S ;
(3)如果 x^2+x^3∈S ,那么 x∈S .
证明:S 至少包含 0、1 之间的两个不同实数.
由(1)得 0∈S ,
由(2)得 2^0+3^0=2∈S ,
令 x^2+x^3=2 ,解得 x=1∈S ,
令 x^2+x^3=1 ,解得 x ≈ 0.75∈S ,
令 x^2+x^3=0.75 ,解得 x ≈ 0.67∈S ,
因此结论成立.(本题实际上是要证明 x^2+x^3=1 有实根 x0 满足 0