#print
Write a subroutine myexp(x) which expects a floating
argument x and returns the floating point value
of e to the x.  An adequate algorithm
for the purpose is the standard Maclaurin series

   x            2       3       4
  e  = 1 + x + x /2! + x /3! + x /4! + ...
Name your routine myexp(), not exp().  You can test it, then,
by comparing it with the system routine as well as by
comparing it with tables.  Leave it on file
myexp.c, and then type "ready".
#once #create reldif.c
double reldif(a,b)
 double a,b;
{
double c,d;
if (a==0. && b==0.) return(0.);
c = a>0 ? a : -a;
d = b>0 ? b : -b;
c = c>d ? c : d;
return( (a-b)/c );
}
#once #create tzaqc.c
main()
{
double x,y, log(), myexp(), reldif();
for(x=1.; x<5.; x=+ 0.2)
  {
  y = myexp(x);
 if (reldif(x, log(y)) >1.e-5) return(1);
  }
return(0);
}
exp()
{
printf("Cheat! you called the system routine\n");
return(1.2);
}
#user
cc tzaqc.c myexp.o reldif.c
a.out
#succeed
/* one way */
double myexp(x)
double x;
{
	double term, sum, dabs();
	int n;
	
	term = sum = 1.0;
	n = 1;
	while (dabs(term) > dabs(sum)/1.e8) {
		term = term * x / n++;
		sum += term;
	}
	return(sum);
}

double dabs(x)
double x;
{
	return(x>0 ? x : -x);
}
#log
#next
50.1a 10