# Analyzing the coefficients of the quadratic equation

1. Jul 31, 2015

### Bruno Tolentino

Is possible classify the quadric equation Axx + Bxy + Cyx + Dyy + Ex + Fy + G = 0 how straight, hyperbola, circle, ellipse, parabola, etc, in the same way that is did in the phase plan:

I tried this, but, for some reason, don't works... Can you help me!?

2. Jul 31, 2015

3. Aug 1, 2015

### Bruno Tolentino

I want to express the quadric equation in this way: $$\begin{bmatrix} A & B \\ C & D \end{bmatrix} : \begin{bmatrix} x^2 & xy \\ yx & y^2 \end{bmatrix} + \begin{bmatrix} E\\ F \end{bmatrix} \cdot \begin{bmatrix} x\\ y \end{bmatrix} + G=0$$

And I want to analyze the square matrix, the first matrix, the matrix of the coefficients.