Math Class

The Math class is a wrapper class for a set of useful mathematical functions and constants.  All of the methods and fields are static, and there is no public constructor. 

java.lang

java.lang.Object

double E

The base of natural logarithms, 2.718...

double PI

The ratio of the circumference of a circle to its diameter, 3.14159...

static double abs (double)

Returns the absolute value of the argument

static float abs (float)

Returns the absolute value of the argument

static int abs (int)

Returns the absolute value of the argument

static long abs (long)

Returns the absolute value of the argument

static double acos (double)

Returns the arccos of the argument (in radians), in the range (0, pi)

static double asin (double)

Returns the arcsin of the argument (in radians), in the range (-pi/2, pi/2)

static double atan (double)

Returns the arctan of the argument (in radians), in the range (-pi/2, pi/2)

static double atan2 (double y, double x)

Returns the arctan of y/x (in radians), in the range [0, 2*pi)

static double cos (double)

Returns the cosine of the argument (in radians)

static double exp (double)

Returns e raised to the power of the argument

static double log (double)

Returns the natural logarithm of the argument

static double pow (double base, double exp)

Returns the base raised to the exp power

static double random ()

Returns a pseudorandom number in the range [0, 1)

static long round (double)

Returns the nearest integer to the argument

static int round (float)

Returns the nearest integer to the argument

static double sin (double)

Returns the sine of the argument (in radians)

static double sqrt (double)

Returns the square root of the argument

static double tan (double)

Returns the tangent of the argument (in radians)

static double toDegrees (double)

Returns the conversion of the argument from radians to degrees

static double toRadians (double)

Returns the conversion of the argument from degrees to radians

import java.applet.Applet;
import java.awt.*;

public class Trig1 extends Applet {

  public void paint (Graphics g) {
    double x;
    double y;
    int X0;
    int Y0;
    int X1;
    int Y1;
    int X2;
    int Y2;
    int C1;
    int C2;
    int T1;
    int T2;
    double ScaleX;
    double ScaleY;
    double Inc;

    Y0 = 160;
    x = - 5.0;
    ScaleX = 50;
    ScaleY = 50;
    Inc = 1./ScaleX;
    X0 = 250;
    y = Math.sin (x);
    X1 = X0 + (int) Math.round (ScaleX * x);
    Y1 = Y0 - (int) Math.round (ScaleY * y);
    y = Math.cos (x);
    C1 = Y0 - (int) Math.round (ScaleY * y);
    y = Math.tan (x);
    T1 = Y0 - (int) Math.round (ScaleY * y);
    g.setColor (Color.black);
    g.drawLine (0, Y0, X0 + X0, Y0);
    g.drawLine (X0, 0, X0, Y0 + Y0);
    while (x < 5.0) {
      X2 = X0 + (int) Math.round (ScaleX * x);
      y = Math.tan (x);
      T2 = Y0 - (int) Math.round (ScaleY * y);
      if (Math.abs (y) < 4.0) {
        g.setColor (Color.green);
        g.drawLine (X1, T1, X2, T2);
      }
      y = Math.sin (x);
      Y2 = Y0 - (int) Math.round (ScaleY * y);
      g.setColor (Color.blue);
      g.drawLine (X1, Y1, X2, Y2);
      y = Math.cos (x);
      C2 = Y0 - (int) Math.round (ScaleY * y);
      g.setColor (Color.red);
      g.drawLine (X1, C1, X2, C2);
      X1 = X2;
      Y1 = Y2;
      C1 = C2;
      T1 = T2;
      x += Inc;
    }
    g.setColor (Color.red);
    g.drawString ("y = cos (x)", X0 - 60, Y0 - (int) ScaleY - 10);    
    g.setColor (Color.blue);
    g.drawString ("y = sin (x)", X0 + 10, Y0 + 20);    
    g.setColor (Color.green);
    g.drawString ("y = tan (x)", X0 + 70, Y0 - 2 * ((int) ScaleY)); 
    setBackground (Color.white);   
  }

}