Discriminant of a quadratic equation in 2 variables

Ashu2912 · Nov 9, 2011

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

Stephen Tashi · Nov 10, 2011

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

Ashu2912 · Nov 10, 2011

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...

Stephen Tashi · Nov 10, 2011

What is the title of your text?

Wolfram has a page on the discriminant of a quadratic curve and it gives a different formula:
http://mathworld.wolfram.com/QuadraticCurveDiscriminant.html

Discriminant of a quadratic equation in 2 variables

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