Math.Sqrt(Double) 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
回傳指定數字的平方根。
public:
static double Sqrt(double d);public static double Sqrt(double d);static member Sqrt : double -> doublePublic Shared Function Sqrt (d As Double) As Double參數
- d
- Double
該數的平方根。
傳回
以下表格中的其中一個數值。
d 參數 | 回傳價值 |
|---|---|
| 零或正 | 的 d正平方根。
|
| 陰性 | NaN |
| 平等 NaN | NaN |
| 平等 PositiveInfinity | PositiveInfinity |
範例
正方形面積的平方根代表該正方形任一邊的長度。 以下範例顯示了美國部分城市的面積，並讓人感受到如果每個城市以正方形表示時的大小。
// 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
open System
// Create a list containing the area of some cities.
let areas =
[ "Sitka, Alaska", 2870.3
"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("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
