polynomial polynomial :: derivative(void)
{
if(!isEmpty())
{
double *coef;
coef = new double[(_degree-1)];
for(int i=0; i<(_degree); i++)
{
coef[i]=(i+1)*(_coef[i+1]);
}

Checking the variable "outpoly I observe its member variables. Checking with other inputs I observe only the pointer "_coef" becomes erroneous.

Thank you for the suggestion of using an explicit...

I checked the debugger and it deletes the data just right before it returns. I don't seem to get errors at cout, but since the data is invalid error does pop up.
I'll check on it more closely, but...

The "outpoly" within the function "derivative" is supposed to return the derivative of the polynomial it is called from.

I followed my debugger and it showed me that the program cleared the memory...

polynomial polynomial :: derivative(void)
{
polynomial outpoly;
outpoly._coef = new double [_degree];
outpoly._degree = (_degree-1);
for(int i=0; i<(_degree); i++)
{...

Thank you jonsca, I eventually got the solution with some research. I didn't, rather, couldn't, use your resource though. I couldn't open it. :(

Thank you. :D

#include <cmath>

long double NR(long double sample)
{
return (abs(f(sample)))<=1e-10 ? sample: NR( (sample - f(sample)/fp(sample)));
}

long double f(long double sample)
{
return...

I figured as much with OS X, but thanks for the heads up.

That's funny because I have Vista installed on a 25 Gb partition and XP on a 15 GB partition with all my data on a 26 GB partition. I also have a hidden recovery partition, all of which would add up...