Question

what exactly is a 'real number' does that mean whole # or can it be like .5?

Answer 1

yeah, i think real numbers can be basically any number on the number line (including decimals and fractions) according to wikipedia it includes integers fractions and unrational numbers (Pi for example)

Answer 2

whole # - this is not defined by mathematicians (use integer, positive integer, natural number, etc)

Answer 3

a real number is any number that appears on the real line; i.e. does not have an imaginary (complex) part
complex numbers involve \[i=\sqrt{-1}\]which is not a real number, because there is no real number \((-\infty,\infty)\) number that satisfies \(\sqrt{-1}\)
our guesses might be 1 and -1, but...\[1\cdot1=1\neq-1\]and\[(-1)(-1)=1\neq-1\]so there is no "real" number that satisfies the expression
real numbers in no way have to be whole numbers

Answer 4

so, .5 is a real number?

Answer 5

does it have any complex part in it ? an \(i\) or \(\sqrt1\) ?

Answer 6

I mean \(\sqrt{-1}\)

Answer 7

0.5 + 0i

Answer 8

oh you cheater :P

Answer 9

:-)

Answer 10

it must have a non-zero complex part to be exact

Answer 11

...if it is *not* to be a real number, that is

Answer 12

But isn't the real line part of the complex plane?

Answer 13

all real numbers are complex, not all complex are real
if I am phrasing it poorly above I am only being too lazy since I'm about to leave, sorry :/

Answer 14

s'K, just kidding a bit, it's the algebraist in me......

Answer 15

good habit ;)

Answer 16

I bet OP wish she never asked now.....:-)

Answer 17

so is .5 a real number???

Answer 18

A simple answer is that pretty much all the numbers you are used to (including 0.5) are real.