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 Subject: Answering square roots Category: Reference, Education and News > Education Asked by: hookem03-ga List Price: \$5.50 Posted: 19 Oct 2006 20:21 PDT Expires: 18 Nov 2006 19:21 PST Question ID: 775230
 ```What is the square root of 25? The answer should obviously be 5, since 5*5=25. But could -5 work as well such as, -5 * -5 = 25. If the latter is true, what would be the answer to negative of a square root of 25 (-(v25))? Would it still be positive and negative 5?``` ```Hi hookem03, Like other positive real numbers, 25 has two square roots, 5 and -5. As you guessed, the negative of the square root of 25 is the same two numbers, since the 5 becomes -5 when negated, and similarly, the -5 becomes 5. The positive square root is called the "principal square root," and in some contexts, that may be what is meant by a reference to the square root of a number. But both the positive and negative square roots really are square roots. Additional Links Wikipedia on square roots http://en.wikipedia.org/wiki/Square_root Square root article on Wolfram MathWorld http://mathworld.wolfram.com/SquareRoot.html --efn```  