User talk:Amcnea

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Your edits to Square root

Your recent edit to the page Square root appears to have added incorrect information and has been reverted or removed. All information in this encyclopedia must be verifiable in a reliable, published source. If you believe the information that you added was correct, please cite the references or sources or before making the changes, discuss them on the article's talk page. Please use the sandbox for any tests that you wish to make. Do take a look at the welcome page if you would like to learn more about contributing to our encyclopedia. Thank you. - DVdm (talk) 23:08, 8 January 2010 (UTC)[reply]

Error: sqrt(xy) is not +/- sqrt(x) sqrt(y))

What are you talking about?
sqrt(xy) = +/- sqrt(x) * sqrt(y)
Feel free to offer just 1 example in which this equation is wrong.

Here is one example of the equation you put up being wrong:
sqrt(-3 * 3) = sqrt(-3) * sqrt(3)
sqrt(-9) = i*sqrt(3)*sqrt(3)
3i = 3i
You current equation says that this doesn't work.
— Preceding unsigned comment added by Amcnea (talk • contribs)

Please read the opening of the article. It says:

"Every non-negative real number x has a unique non-negative square root, called the principal square root, which is denoted with a radical sign as √.",

so expressions like √(-9) are actually nonsense. The "square root of negative numbers" is discussed further down in the article.

Please sign talk page messages with four tildes (~~~~)? Cheers and enjoy reading the article. DVdm (talk) 12:37, 9 January 2010 (UTC)[reply]