using System;

class Sample {
  static void Main()
  {
    // 3の平方根を求める(Sqrtメソッドを呼び出す)
    double val = Math.Sqrt(3);

    Console.WriteLine(val);
  }
}

Imports System

Class Sample
  Shared Sub Main()
    ' 3の平方根を求める(Sqrtメソッドを呼び出す)
    Dim val As Double = Math.Sqrt(3)

    Console.WriteLine(val)
  End Sub
End Class

using System;
using static System.Math; // Mathクラスの静的メンバをインポート(C# 6.0以降)

class Sample {
  static void Main()
  {
    double val = Sqrt(3); // クラス名を省略して呼び出すことができる

    Console.WriteLine(val);
  }
}

Imports System
Imports System.Math ' Mathクラスのメンバをインポート(VB 7以降)

Class Sample
  Shared Sub Main()
    Dim val As Double = Sqrt(3) ' クラス名を省略して呼び出すことができる

    Console.WriteLine(val)
  End Sub
End Class

using System;
// using System.Math; // usingディレクティブは型名には使用できず、名前空間に対してのみ使用できる

// usingディレクティブで型のエイリアス(別名)を付ける
// ここではSystem.MathクラスにMというエイリアスを与えている
// (M.***と記述するとSystem.Mathのメンバを呼び出せる)
using M = System.Math;

class Sample {
  static void Main()
  {
    double val = M.Sqrt(3); // エイリアスを使って呼び出すことができる

    Console.WriteLine(val);
  }
}

Imports System

' Importsステートメントで型のエイリアス(別名)を付ける
' ここではSystem.MathクラスにMというエイリアスを与えている
' (M.***と記述するとSystem.Mathのメンバを呼び出せる)
Imports M = System.Math 

Class Sample
  Shared Sub Main()
    Dim val As Double = M.Sqrt(3) ' エイリアスを使って呼び出すことができる

    Console.WriteLine(val)
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    // 切り捨て
    Console.WriteLine("Truncate(1.5) = {0}", Math.Truncate(1.5));

    // 次の整数への切り上げ
    Console.WriteLine("Ceiling(1.1) = {0}", Math.Ceiling(1.1));

    // 前の整数への切り下げ
    Console.WriteLine("Floor(1.9) = {0}", Math.Floor(1.9));

    // 四捨五入 (小数点0桁への四捨五入・小数点1桁目での四捨五入)
    Console.WriteLine("Round(0.4) = {0}", Math.Round(0.4, 0, MidpointRounding.AwayFromZero));
    Console.WriteLine("Round(0.5) = {0}", Math.Round(0.5, 0, MidpointRounding.AwayFromZero));
  }
}

Imports System

Class Sample
  Shared Sub Main()
    ' 切り捨て
    Console.WriteLine("Truncate(1.5) = {0}", Math.Truncate(1.5))

    ' 次の整数への切り上げ
    Console.WriteLine("Ceiling(1.1) = {0}", Math.Ceiling(1.1))

    ' 前の整数への切り下げ
    Console.WriteLine("Floor(1.9) = {0}", Math.Floor(1.9))

    ' 四捨五入 (小数点0桁への四捨五入・小数点1桁目での四捨五入)
    Console.WriteLine("Round(0.4) = {0}", Math.Round(0.4, 0, MidpointRounding.AwayFromZero))
    Console.WriteLine("Round(0.5) = {0}", Math.Round(0.5, 0, MidpointRounding.AwayFromZero))
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    Console.WriteLine("{0,6}| {1,12} {2,12} {3,12} {4,16} {5,20}| {0,6}",
                      "value",
                      "Ceiling",
                      "Floor",
                      "Truncate",
                      "Round+ToEven",
                      "Round+AwayFromZero");

    Console.WriteLine(new string('-', 14 * 7));

    for (double d = 2.75; -2.75 <= d; d -= 0.25) {
      Console.WriteLine("{0,6:F2}| {1,12:F2} {2,12:F2} {3,12:F2} {4,16:F2} {5,20:F2}| {0,6:F2}",
                        d,
                        Math.Ceiling(d),
                        Math.Floor(d),
                        Math.Truncate(d),
                        Math.Round(d, MidpointRounding.ToEven),
                        Math.Round(d, MidpointRounding.AwayFromZero));
    }
  }
}

Imports System

Class Sample
  Shared Sub Main()
    Console.WriteLine("{0,6}| {1,12} {2,12} {3,12} {4,16} {5,20}| {0,6}", _
                      "value", _
                      "Ceiling", _
                      "Floor", _
                      "Truncate", _
                      "Round+ToEven", _
                      "Round+AwayFromZero")

    Console.WriteLine(New String("-"c, 14 * 7))

    For d As Double = 2.75 To -2.75 Step -0.25
      Console.WriteLine("{0,6:F2}| {1,12:F2} {2,12:F2} {3,12:F2} {4,16:F2} {5,20:F2}| {0,6:F2}", _
                        d, _
                        Math.Ceiling(d), _
                        Math.Floor(d), _
                        Math.Truncate(d), _
                        Math.Round(d, MidpointRounding.ToEven), _
                        Math.Round(d, MidpointRounding.AwayFromZero))
    Next
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    int a = int.MaxValue;
    int b = 2;

    Console.WriteLine("{0} * {1} = {2}", a, b, Math.BigMul(a, b));

    // 同じ値の積を*演算子で求めるとオーバーフローとなる
    Console.WriteLine("{0} * {1} = {2}", a, b, a * b);
  }
}

Imports System

Class Sample
  Shared Sub Main()
    Dim a As Integer = Integer.MaxValue
    Dim b As Integer = 2

    Console.WriteLine("{0} * {1} = {2}", a, b, Math.BigMul(a, b))

    ' 同じ値の積を*演算子で求めるとオーバーフローとなる
    Console.WriteLine("{0} * {1} = {2}", a, b, a * b)
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    int a = 5;
    int b = 3;
    int div, rem; // Math.DivRemメソッドの結果を格納する変数

    // aとbの商と剰余を求める
    // 商は戻り値divに、剰余はoutパラメータのremに代入される
    div = Math.DivRem(a, b, out rem);

    Console.WriteLine("{0}÷{1} = {2}…{3}", a, b, div, rem);

    // aとbの商と剰余を演算子によって個別に求めた場合
    div = a / b;
    rem = a % b;

    Console.WriteLine("{0}÷{1} = {2}…{3}", a, b, div, rem);
  }
}

Imports System

Class Sample
  Shared Sub Main()
    Dim a As Integer = 5
    Dim b As Integer = 3
    Dim div, rm As Integer ' Math.DivRemメソッドの結果を格納する変数

    ' aとbの商と剰余を求める
    ' 商は戻り値divに、剰余はoutパラメータのremに代入される
    div = Math.DivRem(a, b, rm)

    Console.WriteLine("{0}÷{1} = {2}…{3}", a, b, div, rm)

    ' aとbの商と剰余を演算子によって個別に求めた場合
    div = a \ b
    rm  = a Mod b

    Console.WriteLine("{0}÷{1} = {2}…{3}", a, b, div, rm)
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    // 累乗 (平方・立方)
    Console.WriteLine("3^2 = {0}", Math.Pow(3, 2));
    Console.WriteLine("2^3 = {0}", Math.Pow(2, 3));

    // 平方根
    Console.WriteLine("√2 = {0}", Math.Sqrt(2));
    Console.WriteLine("√4 = {0}", Math.Sqrt(4));

    // 累乗根 (立方根)
    Console.WriteLine("^3√8 = {0}", Math.Pow(8, 1.0 / 3.0));
  }
}

Imports System

Class Sample
  Shared Sub Main()
    // 累乗 (平方・立方)
    Console.WriteLine("3^2 = {0}", Math.Pow(3, 2))
    Console.WriteLine("2^3 = {0}", Math.Pow(2, 3))

    // 平方根
    Console.WriteLine("√2 = {0}", Math.Sqrt(2))
    Console.WriteLine("√4 = {0}", Math.Sqrt(4))

    // 累乗根 (立方根)
    Console.WriteLine("^3√8 = {0}", Math.Pow(8, 1 / 3))
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    Console.WriteLine(Math.Exp(1));
    Console.WriteLine(Math.Pow(Math.E, 1)); // Math.Powメソッドを使って求める場合
    Console.WriteLine();

    Console.WriteLine(Math.Exp(2));
    Console.WriteLine(Math.Pow(Math.E, 2)); // Math.Powメソッドを使って求める場合
    Console.WriteLine();
  }
}

Imports System

Class Sample
  Shared Sub Main()
    Console.WriteLine(Math.Exp(1))
    Console.WriteLine(Math.Pow(Math.E, 1)) ' Math.Powメソッドを使って求める場合
    Console.WriteLine()

    Console.WriteLine(Math.Exp(2))
    Console.WriteLine(Math.Pow(Math.E, 2)) ' Math.Powメソッドを使って求める場合
    Console.WriteLine()
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    // 自然対数ln
    Console.WriteLine("ln(2.7182818)    = {0}", Math.Log(2.7182818)); // eを底とした自然対数
    Console.WriteLine("log_e(2.7182818) = {0}", Math.Log(2.7182818, Math.E)); // 上と同等
    Console.WriteLine();

    // 常用対数log10
    Console.WriteLine("log_10(2)   = {0}", Math.Log10(2)); // 10を底とした常用対数
    Console.WriteLine("log_10(100) = {0}", Math.Log(100, 10)); // 上と同等
    Console.WriteLine();

    // 底を2とした対数
    Console.WriteLine("log_2(2) = {0}", Math.Log(2, 2));
    Console.WriteLine("log_2(4) = {0}", Math.Log(4, 2));
    Console.WriteLine();
  }
}

Imports System

Class Sample
  Shared Sub Main()
    ' 自然対数ln
    Console.WriteLine("ln(2.7182818)    = {0}", Math.Log(2.7182818)) ' eを底とした自然対数
    Console.WriteLine("log_e(2.7182818) = {0}", Math.Log(2.7182818, Math.E)) ' 上と同等
    Console.WriteLine()

    ' 常用対数log10
    Console.WriteLine("log_10(2)   = {0}", Math.Log10(2)) ' 10を底とした常用対数
    Console.WriteLine("log_10(100) = {0}", Math.Log(100, 10)) ' 上と同等
    Console.WriteLine()

    ' 底を2とした対数
    Console.WriteLine("log_2(2) = {0}", Math.Log(2, 2))
    Console.WriteLine("log_2(4) = {0}", Math.Log(4, 2))
    Console.WriteLine()
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    // log_10(0)
    Console.WriteLine(Math.Log10(0));

    // log_1/2(0)
    Console.WriteLine(Math.Log(0, 0.5));
  }
}

Imports System

Class Sample
  Shared Sub Main()
    ' log_10(0)
    Console.WriteLine(Math.Log10(0))

    ' log_1/2(0)
    Console.WriteLine(Math.Log(0, 0.5))
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    Console.WriteLine("Sin(π/6) = {0}", Math.Sin(Math.PI / 6));
    Console.WriteLine("Cos(π/4) = {0}", Math.Cos(Math.PI / 4));
    Console.WriteLine("Tan(π/3) = {0}", Math.Tan(Math.PI / 3));
    Console.WriteLine();

    double degree = 45.0;
    double radian = Math.PI * degree / 180.0; // 度数法(度)から弧度法(ラジアン)に変換

    Console.WriteLine("Sin({0}°) = {1}", degree, Math.Sin(radian));
    Console.WriteLine("Cos({0}°) = {1}", degree, Math.Cos(radian));
    Console.WriteLine("Tan({0}°) = {1}", degree, Math.Tan(radian));
  }
}

Imports System

Class Sample
  Shared Sub Main()
    Console.WriteLine("Sin(π/6) = {0}", Math.Sin(Math.PI / 6))
    Console.WriteLine("Cos(π/4) = {0}", Math.Cos(Math.PI / 4))
    Console.WriteLine("Tan(π/3) = {0}", Math.Tan(Math.PI / 3))
    Console.WriteLine()

    Dim degree As Double = 45.0
    Dim radian As Double = Math.PI * degree / 180.0 ' 度数法(度)から弧度法(ラジアン)に変換

    Console.WriteLine("Sin({0}°) = {1}", degree, Math.Sin(radian))
    Console.WriteLine("Cos({0}°) = {1}", degree, Math.Cos(radian))
    Console.WriteLine("Tan({0}°) = {1}", degree, Math.Tan(radian))
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    Console.WriteLine("Asin(0.5) = {0}", Math.Asin(0.5));
    Console.WriteLine("Acos(0.7071) = {0}", Math.Acos(0.7071));
    Console.WriteLine("Atan(1.0) = {0}", Math.Atan(1.0));
  }
}

Imports System

Class Sample
  Shared Sub Main()
    Console.WriteLine("Asin(0.5) = {0}", Math.Asin(0.5))
    Console.WriteLine("Acos(0.7071) = {0}", Math.Acos(0.7071))
    Console.WriteLine("Atan(1.0) = {0}", Math.Atan(1.0))
  End Sub
End Class

using System;

class Sample {
  static void Main()
  {
    double x, y;

    x = 1.0; y = 1.0;

    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan2(y, x));
    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan(y / x));
    Console.WriteLine();

    x = 0.0; y = 1.0;

    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan2(y, x));
    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan(y / x));
    Console.WriteLine();

    x = -1.0; y = -1.0;

    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan2(y, x));
    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan(y / x)); // AtanメソッドとAtan2メソッドで結果が異なる
    Console.WriteLine();
  }
}

Imports System

Class Sample
  Shared Sub Main()
    Dim x, y As Double

    x = 1.0 : y = 1.0

    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan2(y, x))
    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan(y / x))
    Console.WriteLine()

    x = 0.0 : y = 1.0

    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan2(y, x))
    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan(y / x))
    Console.WriteLine()

    x = -1.0 : y = -1.0

    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan2(y, x))
    Console.WriteLine("({0}, {1}) : {2}", x, y, Math.Atan(y / x)) ' AtanメソッドとAtan2メソッドで結果が異なる
    Console.WriteLine()
  End Sub
End Class