# Math.Sqrt(Double) メソッド

## 定義

``````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``

d
Double

#### 戻り値

Double

`d` パラメーター 戻り値
0 または正 `d` の正の平方根。
NaN
NaN と等しいNaN
PositiveInfinity と等しいPositiveInfinity

## 例

``````// Create an array containing the area of some squares.
Tuple<string, double>[] areas =
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
``````
``````open System

// Create a list containing the area of some cities.
let areas =
"New York City", 302.6
"Los Angeles", 468.7
"Detroit", 138.8
"Chicago", 227.1
"San Diego", 325.2 ]

printfn "%-18s %14s} %2s\n" "City" "Area (mi.)" "Equivalent to a square with:"

for city, area in areas do
printfn \$"{city,-18} {area,14:N1} {Math.Round(Math.Sqrt(area), 2),14:N2} miles per side"

// 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("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
``````