public class DoMath
1: import java.util.Scanner;
3: /**
4: * A program that uses various Math methods.
5: *
6: * @author Mark Young (A00000000)
7: */
8: public class DoMath {
10: public static void main(String[] args) {
11: // create variables
12: Scanner kbd = new Scanner(System.in);
13: int n, m, big;
14: int a, b, c;
15: double x, y, z;
17: // Introduce yourself
18: System.out.println("\n\n"
19: + "I'm just doin' some math!\n\n");
20: pause();
22: // Math.pow
23: System.out.println("5 squared is " + Math.pow(5, 2));
24: System.out.println("2 to the 5th is " + Math.pow(2, 5));
25: pause();
27: // Math.max
28: System.out.print("Enter two integers: ");
29: n = kbd.nextInt();
30: m = kbd.nextInt();
31: kbd.nextLine();
32: big = Math.max(n, m);
33: System.out.println("The maximum of " + m + " and " + n + " is "
34: + big + ".");
35: System.out.println("I wonder what the minimum is....");
36: pause();
38: // Math.sqrt
39: x = Math.sqrt(10);
40: System.out.println("The square root of 10 is " + x + ".");
41: pause();
43: // Math.hypot
44: System.out.print("Enter two numbers (with decimals): ");
45: y = kbd.nextDouble();
46: z = kbd.nextDouble();
47: kbd.nextLine();
48: System.out.println("The diagonal of a rectangle of width " + y
49: + " and length " + z + " is " + Math.hypot(y, z) + ".");
50: pause();
53: // solve a quadratic equation
54: System.out.print("Enter the a, b, and c co-ordinates "
55: + "of a quadratic equation.\nFor example, "
56: + "the 3, 5, and -1 in 3x^2 + 5x - 1: ");
57: a = kbd.nextInt();
58: b = kbd.nextInt();
59: c = kbd.nextInt();
60: kbd.nextLine();
61: System.out.println("The roots of the equation "
62: + a + "x^2 + " + b + "x + " + c + " are:\n\t"
63: + ((-b + Math.sqrt(b*b - 4*a*c)) / (2 * a)) + " and \n\t"
64: + ((-b - Math.sqrt(b*b - 4*a*c)) / (2 * a)) + ".");
65: pause();
67: // Math.round
68: x = 3.6;
69: m = (int)Math.round(x);
70: System.out.println(x + " rounded off to the nearest int is " + m);
71: System.out.print("Enter two numbers (with decimals): ");
72: y = kbd.nextDouble();
73: z = kbd.nextDouble();
74: kbd.nextLine();
75: n = (int)Math.round(y);
76: m = (int)Math.round(z);
77: System.out.println(y + " rounded off to the nearest int is " + n);
78: System.out.println(z + " rounded off to the nearest int is " + m);
79: x = 3456789012.34567890;
80: m = (int)Math.round(x);
81: System.out.printf("%,.1f rounded off to the nearest int is %,d.\n",
82: x, m);
83: System.out.println("\tor IS it????");
84: pause();
85: }
87: /**
88: * Prompt the user and wait for them to press the enter key.
89: */
90: public static void pause() {
91: Scanner kbd = new Scanner(System.in);
93: System.out.println();
94: System.out.print("Press Enter...");
95: kbd.nextLine();
96: System.out.println();
97: }
99: }