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(2) Declare a double variable called quadratic . Initialize the variable to one

ID: 646840 • Letter: #

Question

(2) Declare a double variable called quadratic. Initialize the variable to one of the roots of the quadratic formula (assuming there are variables called a, b, and c):

(-b + square-root(b^2 - 4ac))/2a

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(3) Convert the following Boolean expression to an equivalent expression that doesn't contain any !'s:

!(grade > 50 || percentAttended >= 0.9)

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(4) Here's code that uses a while-loop. Write a piece of equivalent code (i.e. code that behaves exactly the same for all possible input values) that uses a do-while loop instead.

Scanner keybd = new Scanner (System.in);

int inputValue = keybd.nextInt();

while (inputValue < 10){

   inputValue++;

   System.out.println(inputValue);

}

Explanation / Answer

(2) Declare a double variable called quadratic. Initialize the variable to one of the roots of the quadratic formula (assuming there are variables called a, b, and c):
(-b + square-root(b^2 - 4ac))/2a

double quadratic = (-b + Math.sqrt(b*b - 4*a*c))/(2*a);


(3) Convert the following Boolean expression to an equivalent expression that doesn't contain any !'s:
!(grade > 50 || percentAttended >= 0.9)

!(grade > 50) && !(percentAttended >= 0.9)

grade <=50 && percentAttended<0.9


(4) Here's code that uses a while-loop. Write a piece of equivalent code (i.e. code that behaves exactly the same for all possible input values) that uses a do-while loop instead.
Scanner keybd = new Scanner (System.in);
int inputValue = keybd.nextInt();
while (inputValue < 10){
   inputValue++;
   System.out.println(inputValue);
}


do{
if(inputValue<10){
   inputValue++;
   System.out.println(inputValue);
}
}while (inputValue < 10);