Changes

==Two square roots for each number==

==Two square roots for each number==

All numbers have two square roots, one positive and the other negative:

All numbers have two square roots that differ by a factor of -1:

:<math>3 \cdot 3 = 9</math> and <math>-3 \cdot -3 = 9</math>

:<math>3 \cdot 3 = 9</math> and <math>-3 \cdot -3 = 9</math>

When speaking of "''the'' square root of ''x''", people usually refer to the positive square root. For example:

When speaking of "''the'' square root of ''x''", people usually refer to the positive square root. For example: