Square root any nonnegative number, then the principal square root of −"x" is The right side (as well as its negative) is indeed a square root of −"x", since For every non-zero complex number "z" there exist precisely two numbers "w" such that : the principal square root of "z" (defined below), and its negative. There are two complex numbers that square to a given arbitrary non-zero imaginary number formula_11 with real formula_12 where the two-digit pattern {3, 6} repeats over and over again in the partial denominators. Since , the above is also identical to the following generalized continued fractions: The
Square root nonnegative. The term (or number) whose square root is being considered is known as the "radicand". The radicand is the number or expression underneath the radical sign, in this example 9. Every positive number "a" has two square roots: , which is positive, and −, which is negative. Together, these two roots are denoted as ± (see ± shorthand). Although the principal square root of a positive number is only one of its two square roots, the designation ""the" square root" is often used to refer to the "principal square root". For positive "a", the principal square root can also