Changes

==Two square roots ==

==Two square roots ==

<math>x^2 = y</math>

<math>\x^2 = y</math>

implies:

implies:

<math>x = |y|</math>.

<math>\x = |y|</math>.

This shows that all numbers other than zero have two square roots, one positive and one negative: <ref>"Note that any positive real number has two square roots, one positive and one negative. For example, the square roots of 9 are -3 and +3, since (-3)^2==(+3)^2==9." [http://mathworld.wolfram.com/SquareRoot.html Wolfram Research] - Eric Weisstein </ref>

This shows that all numbers other than zero have two square roots, one positive and one negative: <ref>"Note that any positive real number has two square roots, one positive and one negative. For example, the square roots of 9 are -3 and +3, since (-3)^2==(+3)^2==9." [http://mathworld.wolfram.com/SquareRoot.html Wolfram Research] - Eric Weisstein </ref>