| MATH1061/MATH7861: Discrete Mathematics | Mathematical forum questions |
Question Posted 10 August
Does
" x 
R,
" y R,
mean the same thing as
" (x,y) R?
Answer
Almost, but there is a slight problem with the brackets around (x,y) since that
is the notation we use to indicate an ordered pair (like a point on the
x,y-plane). So
" x R,
" y R,
means the same thing as
" x,y R.
Question Posted 10 August
The textbook tends to write their equations up differently from ours.
For example, the phrase "for all integers x" in the book would be written as
" integers x,
whereas in class we wrote it as
" x Z.
Are both correct for the assignment?
Answer
Both ways are acceptable for the assignment. I tend to use the second
method because it is shorter.