Math.Sqrt(Double) Math.Sqrt(Double) Math.Sqrt(Double) Math.Sqrt(Double) Method

定義

指定された数値の平方根を返します。Returns the square root of a specified number.

public:
 static double Sqrt(double d);
public static double Sqrt (double d);
static member Sqrt : double -> double
Public Shared Function Sqrt (d As Double) As Double

パラメーター

d
Double Double Double Double

平方根を求める対象の数値。The number whose square root is to be found.

戻り値

次の表に示した値のいずれかOne of the values in the following table.

d パラメーターd parameter 戻り値Return value
0 または正Zero or positive d の正の平方根。The positive square root of d.
Negative NaN
NaN と等しいEquals NaNNaN
PositiveInfinity と等しいEquals PositiveInfinityPositiveInfinity

正方形の領域の平方根は、任意の正方形の辺の長さを表します。The square root of the area of a square represents the length of any side of the square. 次の例では、米国の州の都市の領域を表示し、四角形で表示された場合は、各都市のサイズのような印象を提供します。The following example displays the area of some cities in the United States and gives an impression of each city's size if it were represented by a square.

using System;

public class Example
{
   public static void Main()
   {
      // Create an array containing the area of some squares.
      Tuple<string, double>[] areas = 
                     { Tuple.Create("Sitka, Alaska", 2870.3), 
                       Tuple.Create("New York City", 302.6), 
                       Tuple.Create("Los Angeles", 468.7), 
                       Tuple.Create("Detroit", 138.8), 
                       Tuple.Create("Chicago", 227.1), 
                       Tuple.Create("San Diego", 325.2) };

      Console.WriteLine("{0,-18} {1,14:N1} {2,30}\n", "City", "Area (mi.)", 
                        "Equivalent to a square with:");

      foreach (var area in areas)
        Console.WriteLine("{0,-18} {1,14:N1} {2,14:N2} miles per side", 
                          area.Item1, area.Item2, Math.Round(Math.Sqrt(area.Item2), 2));        
   }
}
// The example displays the following output:
//    City                   Area (mi.)   Equivalent to a square with:
//    
//    Sitka, Alaska             2,870.3          53.58 miles per side
//    New York City               302.6          17.40 miles per side
//    Los Angeles                 468.7          21.65 miles per side
//    Detroit                     138.8          11.78 miles per side
//    Chicago                     227.1          15.07 miles per side
//    San Diego                   325.2          18.03 miles per side
Module Example
   Public Sub Main()
      ' Create an array containing the area of some squares.
      Dim areas() As Tuple(Of String, Double) = 
                     { Tuple.Create("Sitka, Alaska", 2870.3), 
                       Tuple.Create("New York City", 302.6), 
                       Tuple.Create("Los Angeles", 468.7), 
                       Tuple.Create("Detroit", 138.8), 
                       Tuple.Create("Chicago", 227.1), 
                       Tuple.Create("San Diego", 325.2) }

      Console.WriteLine("{0,-18} {1,14:N1} {2,30}", "City", "Area (mi.)", 
                        "Equivalent to a square with:")
      Console.WriteLine()
      For Each area In areas
        Console.WriteLine("{0,-18} {1,14:N1} {2,14:N2} miles per side", 
                          area.Item1, area.Item2, Math.Round(Math.Sqrt(area.Item2), 2))        
      Next
   End Sub
End Module
' The example displays the following output:
'    City                   Area (mi.)   Equivalent to a square with:
'    
'    Sitka, Alaska             2,870.3          53.58 miles per side
'    New York City               302.6          17.40 miles per side
'    Los Angeles                 468.7          21.65 miles per side
'    Detroit                     138.8          11.78 miles per side
'    Chicago                     227.1          15.07 miles per side
'    San Diego                   325.2          18.03 miles per side

適用対象

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