SQRT (number)

  Class:  Elemental function - Generic

  Returns the square root of the argument.

  If the argument is real, its value must be greater than or equal to
  zero.
  +------+---------+----------+------------+-------------+
  | Args | Generic | Specific |  Argument  | Result Type |
  +------+---------+----------+------------+-------------+
  |  1   |  SQRT   | SQRT     | REAL*4     | REAL*4      |
  |      |         | DSQRT    | REAL*8     | REAL*8      |
  |      |         | QSQRT    | REAL*16    | REAL*16     |
  |      |see note | CSQRT    | COMPLEX*8  | COMPLEX*8   |
  |      |         | CDSQRT   | COMPLEX*16 | COMPLEX*8   |
  |      |         | ZSQRT    | COMPLEX*16 | COMPLEX*8   |
  |      |         | CQSQRT   | COMPLEX*32 | COMPLEX*8   |
  +------+---------+----------+------------+-------------+

  Note: The setting of compiler options specifying real
        size can affect CSQRT.

  The result of CSQRT, CDSQRT, and ZSQRT is the principal value, with
  the real part greater than or equal to zero.  If the real part is
  zero, the result is the principal value, with the imaginary part
  greater than or equal to zero.