if z^n=1 whaty is the value of z
1. n is a non zero integer
2. z>0
I thought it was A since, z^n=1 and n is non zero z must be 1 becuase n could've been 0.
why is it both??
gmat prep question
This topic has expert replies
- jayhawk2001
- Community Manager
- Posts: 789
- Joined: Sun Jan 28, 2007 3:51 pm
- Location: Silicon valley, California
- Thanked: 30 times
- Followed by:1 members
1 tells us that z can be +1 or -1. Based on whether n is even or odd,yvonne12 wrote:if z^n=1 whaty is the value of z
1. n is a non zero integer
2. z>0
I thought it was A since, z^n=1 and n is non zero z must be 1 becuase n could've been 0.
why is it both??
we can get z^n = 1. Hence insufficient.
2 tells us that z > 0 which is insufficient by itself. If n is zero, z^n =1 for
any value of z > 0
Taking 1 and 2, we get z = +1.
Hence C