请教gwd第四套math的两道题

xionghuixhs

Q4: For a nonnegative integer n, if the remainder is 1 when 2^n is divided by 3, then which of the following must be true?

                                                                           I.     n is greater than zero

                                                                           II.    3^n=(-3)^n

                                                                           III.    v2^n is an interger

   A: I only        B: II only    C: I and II    D: I and III   E: II and III      (Answer: E, 为设么第三个也对啊， v是多少又不知道咯？

Q29: If x > 0.9, which of the following could be the value of x?

A: v0.81   B: v0.9   C: (0.9)^2  D: (0.9)(0.99)   E: 1- v0.01        (Answer: B   我觉得ABE都可以啊！）

 

fuchaoyang

QUOTE:

Q4: For a nonnegative integer n, if the remainder is 1 when 2^n is divided by 3, then which of the following must be true?

                                                                           I.     n is greater than zero

                                                                           II.    3^n=(-3)^n

                                                                           III.    v2^n is an interger

   A: I only        B: II only    C: I and II    D: I and III   E: II and III      (Answer: E, 为设么第三个也对啊， v是多少又不知道咯？

根据题目意思,n为偶数的时候整除3余数才为1,所以,v2^n就一定是个整数

Q29: If x > 0.9, which of the following could be the value of x?

A: v0.81   B: v0.9   C: (0.9)^2  D: (0.9)(0.99)   E: 1- v0.01        (Answer: B   我觉得ABE都可以啊！）

 A开方后为0.9小于x,E的结果为0.9也小于x

xionghuixhs

为社么啊, 我v的数值还是不知道啊, 2^n是整数但乘上v就不确定拉, 第二题和开方有社么关系啊

lizhihuantu

QUOTE:

为社么啊, 我v的数值还是不知道啊, 2^n是整数但乘上v就不确定拉, 第二题和开方有社么关系啊这儿的v应该代表根号，不是变量

xionghuixhs

I see, I see, thanks