a null set and an empty set, are they the same?

Question

mathteacher1729 · Answer

Hi @sasogeek , in every context I've ever seen, null set and empty set mean the same thing.  A set with no elements.

sasogeek · Answer

well we had an exam and the teacher asked which of the following options was a null set.

a. 
b.{}
c.{0}
d.$\phi $

mathteacher1729 · Answer

Heh. If I were grading this, I'd accept b or d. Perhaps your professor has a preferred notation? Here is the definition from Wolfram Mathworld: http://mathworld.wolfram.com/NullSet.html

sasogeek · Answer

i chose d though

sasogeek · Answer

so i guess i'm wrong...? since $\phi $ denotes {} ?

mathteacher1729 · Answer

To me, this is splitting hairs. I'd ask your professor if s/he has a preferred notation and go with that for future reference.

sasogeek · Answer

i asked him during the test and he said it was meant to confuse us but he'll tell us the answer next class so i look forward to questioning him tomorrow since tomorrow is the next lecture :)

mathteacher1729 · Answer

Strange. Well, to each their own. For me, I try to make definitions and notation as clear as possible from day 1. ;-p But that's me.

sasogeek · Answer

hmmm oh well. i guess i'd never know which answer he's in search of unless he utters it himself. thanks for the help though :) that link helped a bit. and i appreciate your input x