阅读下面材料：随着人们认识的不断深入，毕达哥拉斯学派逐渐承认 2 不是有理数，并给出了证明．假设是 2 有理数，那么存在两个互质的正整数p，q，使得 2 = pq ，于是p= 2 q，两边平方得p2=

题干

阅读下面材料：随着人们认识的不断深入，毕达哥拉斯学派逐渐承认 2 不是有理数，并给出了证明．假设是 2 有理数，那么存在两个互质的正整数p，q，使得 2 =

，于是p= 2 q，两边平方得p²=2q²．因为2q²是偶数，所以p²是偶数，而只有偶数的平方才是偶数，所以p也是偶数．因此可设p=2s，代入上式，得4s²=2q²，即q²=2s²，所以q也是偶数，这样，p和q都是偶数，不互质，这与假设p，q互质矛盾，这个矛盾说明， 2 不能写成分数的形式，即 2 不是有理数．

请你有类似的方法，证明 23 不是有理数．

上一题下一题 0.0难度选择题更新时间:2017-07-27 01:31:40

答案(点此获取答案解析）

解：假设 23 是有理数，

则存在两个互质的正整数m，n，使得

\sqrt[3]{2}

同类题1

还原短文。

My mother is a kind and nice woman. ____ One Sunday night, when I was watching the film Harry Potter very happily. Mother asked me to go to bed. ____ that I didn't move. But for a while, I noticed that she didn't say anything. ____ I was so sad that I went into my room and cried. I thought "I have only two nights in a week to enjoy the TV. ____" The next day she cooked and talked with me as usual. I pretended not to hear, but she didn't mind and told me why she didn't allow me to watch TV ____ Then I understood her. I love my mother.

A. But she is very strict with me.

B. Because she wanted me to have a good rest.

C. Then she got angry and turned off the TV.

D. I love the film so much.

E. Why doesn't mother allow me to watch TV?

shū
各____己见	神经中____
____途同归	____眉展眼
zhēng
____月	____夺
____扎	____狞
____汽

题干

答案(点此获取答案解析）

同类题1

同类题2

同类题3

同类题4

同类题5