Is the square root of 0 undefined or 0, and why?

The square root of zero would be zero, because zero multiplied by itself (or zero squared) would equal zero.

'0' would be the answer to that question. A squared root means times itself...similiar to the number '1' any root squared, cubed, fourth, etc..will always be '1' just like '0's will always be '0'.

square root function must be valid for the two dimension objects. 0 has no dimension it can be represented as point . 1 can be represent horizantal or vertical length of a line. And 1 square is represented a square box. and square root of 1 square can be a 1 unit length horizantal line or a 1 unit length vertical line length when you take a square root function you make a dimensional conversion.there fore there is two root even you take root of 1.. but zero has no dimension because of that zero can't have a square root neither other power of roots..

0
I knew that when I was eighteen hundred days

Yes, again. See http://www.answerbag.com/q_view/64595

Yes it's zero. Zero times Zero = Zero

The square root of 0, just as all strictly positive integer roots of 0 has the value 0, because all strictly positive powers of 0 are 0:
0=0^1=0^2=0^3=0^4=0^5 etc
http://en.wikipedia.org/wiki/Nth_root
Eine interessante discussion about the 0th power of 0 can be found here:
http://en.wikipedia.org/wiki/Exponentiation#Zero_to_the_zero_power

------ ADDED ------
The Square Root of Zero is also a movie:
"Zero, a beatnik who makes up true-confession stories but never writes them down, imagines that he and his friend Alan, a painter, go camping on an island in Maine. Alan makes the acquaintance of Jane, a young woman who with her wealthy parents is also camping on the island. Zero is left to a dull, platonic relationship with Jane's mother May, a writer of squalid dramas. Her husband Arch spends his time on his yacht with Nell, a vacationing prostitute. Alan becomes frightened when he learns that Jane might be pregnant, and he and Zero depart after staging a mock drowning and funeral."
Source and further information:
http://www.tcm.com/tcmdb/title.jsp?stid=558162

Take a step back from the question. Is zero a number? Zero is neither positive or negative. It is the null dividing line between positive and negative. There for 0 cannot have any square root other than 0.

It would be zero.
the square root of 9 is 3,...because if you multiply 3 by itself it equals nine.
When you multiply zero by zero, you still have zero

u get zero.0 x 0 is 0.

yes, zero times zero is zero so logicaly the square root of zero would be zero, but can you not also multiply ANY number by zero and still get....zero. the square root of a number is the ONLY number that can be multiplied by itself to get the original such that the only way to get a product of 9 in 3x3. but there are an infinity number of ways to get a product of zero.

0x0=0
10x0=0
100,000,000,000,000,000,000x0=(still and always will be) 0

actually anything raised to the power of zero is one. check your math on that bud.

Anything to the square root of 0 is 1. Not one powered, but just 1.0 as a number itself.

Example-

9^0

This will equal 1, not 9.

Or unless you meant that the square root of zero would be zero, because zero multiplied by itself (or zero squared) would equal zero.

Zero. The number of jobs for people who can recite details of old TV programmes is zero. Always has been, always will be.

0 is the swuare root of zero, although i have to disagree with an answer at the top. 0 to the 0th power is one, because by rule anything to the 0 power is 1.

For any root of Zero the answer is infinite or not defined!!

explaination:

x=0^y
ln x=y ln 0
ln 0= not defined
so x= e^ not defined=not defined !!

The square root of zero is zero.