Prep T2-PS-29

[w062611]

If n denotes a number to the left of 0 on the number line such that the square of n is less than 1/100, then the reciprocal of n must be

(A) less than -10
(B) between -1 and
(C) between and 0
(D) between 0 and
(E) greater than 10

答案為 A

不太懂題目的意思

可以麻煩高手指導一下嗎

感謝了

[little8]

n是比零小的數,n的平方數小於1/100,請問n的倒數是多少? reciprocal 倒數
n既然比零小,必定是負;
平方數又為分數,表示n介於-1和0之間,至少為-1/11,
所以倒數一定<-10
因此答案A

我非高手,只是對題目的了解,請參考嚕~

[chris8888]

If n denotes a number to the left of 0 on the number line such that the square of n is less than 1/100, then the reciprocal of n must be

(A) less than -10
(B) between -1 and
(C) between and 0
(D) between 0 and
(E) greater than 10

n的square根據題目要小於 1/100
所以有可能是1/121, 1/144, 1/169, 1/196 ... <== 通通小於1/100
因此可以推論n本來是-1/11, -1/12, -1/13, -1/14 ...
倒數就是 -11, -12, -13, -14 ... 相乘後為1 is reciprocal
得証 n is less than -10