x = 10;
 n = 30;

 disp( sprintf('x = %0.5g',x))
 disp( sprintf('number of terms = %d',n) )
 
 [s,terms]  = expX(x,n);
 diff = exp(x) - s
 relerr = diff/exp(x)
 plot(terms,'linewidth',1.8)
 hold
 plot(terms,'*','linewidth',1.8)
 hold 
 pause

 x = -x;
 
 disp( sprintf('x = %0.5g',x))
 disp( sprintf('number of terms = %d',n) )

 [s,terms]  = expX(x,n);
 diff = exp(x) - s
 relerr = diff/exp(x)
 plot(terms,'linewidth',1.8)
 hold
 plot(terms,'*','linewidth',1.8)
 hold 
 pause

 disp(' Computation with better exponential approximation')

 [s,terms]  = expF(x);

 disp( sprintf('x = %0.5g',x))
 disp( sprintf('number of terms = %d',length(terms)) )
 
 diff = exp(x) - s
 relerr = diff/exp(x)
 plot(terms,'linewidth',1.8)
 hold
 plot(terms,'*','linewidth',1.8)
 hold