How do you classify the conic x^2+4y^2-8x+3y+12=0?

1 Answer
Jan 20, 2017

x^2+4y^2-8x+3y+12=0 is an ellipse.

Explanation:

Let the equation be of the type Ax^2+Bxy+Cy^2+Dx+Ey+F=0

then if

B^2-4AC=0 and A=0 or C=0, it is a parabola

B^2-4AC<0 and A=C, it is a circle

B^2-4AC<0 and A!=C, it is an ellipse

B^2-4AC>0, it is a hyperbola

In the given equation x^2+4y^2-8x+3y+12=0

A=1, B=0 and C=4

Therefore, B^2-4AC=0^2-4xx1xx4=-16<0 and A!=C

Hence, x^2+4y^2-8x+3y+12=0 is an ellipse.
graph{x^2+4y^2-8x+3y+12=0 [1.302, 6.302, -1.64, 0.86]}