Taking reciprocal changes the direction of the inequality. Why the same thing is not applicable here?magizhan wrote:n is a negative number. If n^2 < 1/100 then n<-1/10. Therefore the reciprocal of n, 1/n < -10.
Answer: A
papumba2011 wrote:Taking reciprocal changes the direction of the inequality. Why the same thing is not applicable here?magizhan wrote:n is a negative number. If n^2 < 1/100 then n<-1/10. Therefore the reciprocal of n, 1/n < -10.
Answer: A
I approached in a similar fashion without doing the reciprocality step in the beginning.kevincanspain wrote:papumba2011 wrote:Taking reciprocal changes the direction of the inequality. Why the same thing is not applicable here?magizhan wrote:n is a negative number. If n^2 < 1/100 then n<-1/10. Therefore the reciprocal of n, 1/n < -10.
Answer: A
Including a few more steps should answer your question:
n^2 < 1/100
1/n^2 > 100
1/|n| > 10
-1/n > 10
1/n < -10
Remember : the positive square root of n^2 is |n|
|n| = -n if n < 0
a^2 < b^2 implies that |a| < |b|
certainly the fastest way to do this is to pick a number.papumba2011 wrote: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
1) less than -10
2) between -1 and -1/10
3) between -1/10 and 0
4) between 0 and 1/10
5) greater than 10
