Exercises 5.2

1. yes

2. no

3. yes

4. yes

5. 5

6. out of range

7. 0

8. if (taxCode == ‘T’)

price += (taxRate * price);

9. if (code == 1)

{

int x = theKeyboard.readInt();

int y = theKeyboard.readInt();

theScreen.println((x+y));

}

10. if ((0 < a) && (a < 5))

b = 1 / (a * a);

else

b = a * a;

11.

public static double cost(int distance)

{

if (distance >= 1000)

return 12.00;

else if (distance > 500)

return 10.00;

else if (distance > 100)

return 8.00;

else

return 5.00;

}

12.

/* rootsAreReal(a, b, c) returns true if a quadratic function has

* real roots and false if not. This is based on the coefficients

* a, b, and c.

*

* Receive: a, b, and c, the coefficients of a quadratic equation.

* Return: true if the roots are real, false if not

*/

public static boolean rootsAreReal(double a, double b, double c)

{

return (b * b - 4 * a * c >= 0);

}

13.

/* printPollutionClass(index) outputs a string

* corresponding to the given pollution index.

*

* Receive: index, a pollution index

* Output: the pollution class

*/

public static void printPollutionClass(double index)

{

Screen theScreen = new Screen();

if (index < 35.0)

theScreen.println("Pleasant\n");

else if (index > 60.0)

theScreen.println("Hazardous\n");

else

theScreen.println("Unpleasant\n");

}

14.

/* classifyWindChill(windChill) will classify wind chill's

* effect on a person.

*

* Receive: windChill, the value of a wind chill.

* Output: the classification of the wind chill.

*/

public static void classifyWindChill(double windChill)

{

Screen theScreen = new Screen();

if (windChill >= 10)

theScreen.println("Not dangerous or unpleasant\n");

else if (windChill >= -10)

theScreen.println("Unpleasant\n");

else if (windChill >= -30)

theScreen.println("Frostbite is possible\n");

else if (windChill >= -70)

theScreen.println("Dangerous: Frostbite likely\n");

else

theScreen.println("Instant Ice Cube: "

+ "Frostbite in 30 seconds\n");

}