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### SqRt

#### Synopsis

    function SqRt (x: real_type): real_type;

or

    function SqRt (z: complex_type): complex_type;

#### Description

Returns the positive square root of the argument.

For real arguments, it is an error if the argument is negative.

For complex arguments, `SqRt` returns the principal value of the root of the argument, i.e. the root with positive real part, or, if the real part is zero, that one with positive imaginary part.

#### Conforming to

The function `SqRt` is defined in ISO 7185 Pascal; its application to complex values is defined in ISO 10206 Extended Pascal.

#### Example

    program SqRtDemo;

    var
      m1: Complex;

    begin
      m1 := Cmplx (-1, 0);  { -1 }
      WriteLn (Re (SqRt (m1)) : 6 : 3, Im (SqRt (m1)) : 6 : 3);
        { yields 1.000 -1.000, i.e. the imaginary unit, i }
    end.

#### See also

pow, Sqr, Operators.