# Discriminant of a quadratic equation in 2 variables

1. Nov 9, 2011

### Ashu2912

Can anyone tell me how to calculate the discriminant of a general equation of 2 degree in 2 variables, ax$^{2}$+by$^{2}$+2gx+2fy+2hxy+c=0? Thanks!!!

2. Nov 10, 2011

### Stephen Tashi

I've never seen a textbook that defined the descriminant for a polynomial of two variables. How do your materials define it?

3. Nov 10, 2011

### Ashu2912

In my text it is defined as abc+2gfh-a(f sq.)-b(g sq.)-c(h sq.). I just want to know how is it derived and what is it's significance and implication....

4. Nov 10, 2011