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Hi!   Hi!           Start main()

Try stepping through the code


  Value and type of last evaluated expression: Address of array element: Address of array elementx:  (none)

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Code

 Header...

 int main(){
   ... 

»  double x;

»  x=sqrt(2.0);

»  if (x*x==2.0) // Wrong!
    printf("x*x is exactly 2\n");
  else 
    printf("x*x - 2 is %g\n", x*x-2.0);

»  if (fabs(x*x-2.0)<1e-6) // Right
    printf("Close enough!\n");

  // Now let's see what happens when we use abs() by mistake
»  x=x+0.1;
»  if (abs(x*x-2.0)<1e-6) 
    printf("Should have used fabs()!\n");

»  return 0;

}

Data

x (double)
128
4.94021057e-270

Memory

main()

128
129
130
131
132
133
134
135
x = 4.94021057e-270

NB: the actual memory address of each variable is the
address shown plus 4290662912 (0xFFBE5200).

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.
Show output (Before looking at the output, work out what you think it put should be and see if you are right.)

Output

x*x - 2 is 4.44089e-16
Close enough!
Should have used fabs()!
                                                                                                                                                                                                                                                                       
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