Chapter 3 Exercises

Chapter 3 Exercises
PG 190 Number 6
public class Pg180_6
{
    public static void main(String[] args)
    {
         int x= Calculate(4,-5);
         System.out.println(x);
    }
    public static int Calculate(int x, int y)
    {
        return(Math.abs(Math.max(x,y)));
    }
}

Pg 190 Number 8
public class Pg190_8
{
    public static void main(String[] args)
    {
        int a = 1;
        int b = 3;
        int c = 2;
        double xvertex=-(b/(2*a));
        double discr = discrim(a,b,c)/2*a;
        double x1 = xvertex+discr;
        double x2 = xvertex-discr;
        System.out.println(x1);
        System.out.println(x2);
    }
    public static double discrim(int a, int b, int c)
    {
        return(Math.sqrt(b*b-4*a*c));
    }
}

Pg 190 Number 10
public class Pg190_10
{
    public static void main(String[] args)
    {
        double radius = 2.0;
        double area = Calculate(radius);
        System.out.println("area =" + area );
    }
    public static double Calculate(double x)
    {
        return(Math.PI*(x*x));
    }
}

Pg 190 Number 12
public class Pg190_12
{
    public static void main(String[] args)
    {
        double a = 6.23;
        double b = 5;
        double notation = Calculate(a, b);
        System.out.println("Scientific Notation form of the number is " + notation);
    }
    public static double Calculate(double a, double b)
    {
        return(a*(Math.pow(10,b)));
    }
}

Pg 191 Number 14

public class Pg191_14
{
    public static void main(String[] args)
    {
        double radius = 3.0;
        double height = 4.5;
        double surfacearea = cylinderSurfaceArea(radius, height);
        System.out.println("The Surface Area of the Cylinder is " + surfacearea);
    }
    public static double cylinderSurfaceArea(double r, double h)
    {
        return((2*(Math.PI * (r*r))) + (2*r*h*Math.PI));
    }
}

Pg 191 Number 16

public class Pg191_16
{
    public static void main(String[] args)
    {
        double sideA = 8;
        double sideB = 5.2;
        double sideC = 7.1;
        double area = triangleArea(sideA, sideB, sideC);
        System.out.println("The area of the triangle is " + area);
    }
    public static double triangleArea(double a, double b, double c)
    {
        double s = (a + b + c)/2;
        return(Math.sqrt(s*(s - a)*(s - b)*(s - c)));
    }
}

Pg 191 Number 18

import java.util.*;
public class Pg191_18
{
    public static void main(String[] args)
    {
        String str1 = "hey now";
        for(int i; i <= str1.length(); i++)
        {
            System.out.println(str1.charAt(i+1));
        }
    }
}

Pg 191 Number 20

import java.util.*;
public class Pg191_20
{
    public static void main(String[] args)
    {
        Scanner console = new Scanner(System.in);
        System.out.println("On what day of the month were you born?");
        int day = console.nextInt();
        System.out.println("What is the name of the month in which you were born?");
        String month = console.next();
        System.out.println("During what year were you born?");
        int year = console.nextInt();
        System.out.println("You were born on "+month +" " + day +"," + year +" You're mighty old!");
    }
}

Pg 191 Number 22

import java.util.*;
public class Pg192_22
{
    public static void main(String[] args)
    {
        Scanner console = new Scanner(System.in);
        System.out.println("What is your GPA?");
        double GPA = console.nextDouble();
        System.out.println("What is your SAT score?");
        double SAT = console.nextInt();
        if( GPA >= 1.9)
        {
            System.out.println("You are accepted!");
        }
        else
        {
            System.out.println("You are rejected!");
        }
        if( SAT >= 900)
        {
            System.out.println("You are accepted!");
        }
        else
        {
            System.out.println("You are rejected!");
        }
    }
}