JAVA中的Math类

public final static double E=2.7182818284590452354
自然对数e

public final static double PI=3.14159265358979323846
圆周率
public static double abs(double a)
public static float abs(float a)
public static int abs(int a)
public static long abs(long a)
绝对值

public static double acos(double a)
反余弦

public static double asin(double a)
反正弦

public static double atan(double a)
反正切

public static double ceil(double a)
返回不小于a的最小倍整数

public static double cos(double a)
余弦

public static double exp(double a)
a的指数

public static double floor(double a)
返回小于或等于a的最大整数

public static double IEEEremainder(double f1,double f2)
返回f1-f2*n,其中n为最接近f1/f2的整数

public static double log(double a)
a的自然对数

public static double max(double a,double b)
返回a,b中的较大值

public static double min(double a,double b)
返回a,b中的较小值

public static double min(double a,double b)
返回a的b次方

public static synchronized double random()
返回随机数 在0.0与1.0间

public static double rint(double a)
返回a最近的整数

public static long round(double a)
返回a四舍五入后的整数

public static double sin(double a)
正弦

public static double sqrt(double a)
平方根

public static double tan(double a)
正切

public static double toDegress(double angrad)
返回弧度angrad相当的角度

public static double toRadians(double anddeg)
返回angdeg相当的弧度

示例:
public class mathex
{
public static void main(String args[])
{
   double r = Math.random();
   int n = (int)(r * 100);
   System.out.print(n+"/n");
   double pi = Math.PI;
   double s = Math.sin((pi / 6) );
   System.out.print(s);
   double root = Math.sqrt(100.0);
   System.out.print("/n"+root + "/n");
   double d = Math.pow(2, 3);
   System.out.print(d);
}