Chapter 7.3, Problem 3CE

To determine

To modify the program (1) so that the computer finds and prints the values of the roots when they are real.

Explanation of Solution

Given:

The quadratic equation is of the form $a{x}^2+bx+c$

Calculation:

The following is the required BASIC Program-

10 INPUT “Enter the value of a”: a

20 INPUT “Enter the value of b”: b

30 INPUT “Enter the value of c”: c

40 LET $D=(b\times b-4\times a\times c)$

50 If $D>=0$

60 LET $x_1=(-(b)+sqrt(D))/2\times a$

70 LET $x_2=(-(b)-sqrt(D))/2\times a$

80 ELSE

90 PRINT “Roots are imaginary”;

100 PRINT “The first root is”: $x_1$

110 PRINT “The second root is”: $x_2$

120 END

DRY RUN of the program:-

INPUT:

Enter the value of a

  $a=2$

Enter the value of b

  $b=5$

Enter the value of c

  $c=2$

OUTPUT:

The first root is $-0.5$

The second root is $-2$