Conic Sections Calculator

Enter the general quadratic equation to identify the type of conic, get its graph, and see the step-by-step solution.

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Analyze the equation \( x^2+y^2-25=0 \) and determine the type of conic it represents.

Equation analysis


Classification: Circle.

Standard form: \( x^2 + y^2 = 25 \)

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ x^2 + y^2 - 25 = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = 1 \quad B = 0 \quad C = 1 \\[0.5em] D = 0 \quad E = 0 \quad F = -25 $$

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = 0 - 4(1)(1) = -4 $$

Since Δ < 0, the equation corresponds to a general ellipse.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(1)(1)(-25) - 2(1)(0)^2 - 2(0)^2(-25) + 2(0)(0)(0) - 2(1)(0)^2 \\[0.5em] \delta = -200 $$

Since δ ≠ 0, the equation does not correspond to a degenerate case.

3. Existence analysis.

To check if the equation corresponds to a real or imaginary ellipse, we use the trace invariant:

$$ A + C = 1 + 1 = 2 $$

Since the sign of A + C is different from the sign of δ, the equation corresponds to a real ellipse. Additionally, since A = C and B = 0, the conic is a circle.

Graph in the Cartesian plane of a circle centered at the origin obtained from the analysis of a general quadratic equation.
Graph of the circle
Determine the type of conic represented by the equation \( 9x^2+16y^2-144=0. \)

General equation analysis


Classification: Non-degenerate ellipse.

Orientation: Horizontal (principal axis parallel to the x-axis).

Standard form: \( \dfrac{x^2}{16} + \dfrac{y^2}{9} = 1 \)

For more information about the conic, check the ellipse calculator.

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ 9x^2 + 16y^2 - 144 = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = 9 \quad B = 0 \quad C = 16 \\[0.5em] D = 0 \quad E = 0 \quad F = -144 $$

We will perform an invariant analysis to determine the conic type.

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = 0 - 4(9)(16) = -576 $$

Since Δ < 0, the equation corresponds to a general ellipse.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(9)(16)(-144) - 2(9)(0)^2 - 2(0)^2(-144) + 2(0)(0)(0) - 2(16)(0)^2 \\[0.5em] \delta = -165888 $$

Since δ ≠ 0, the equation does not correspond to a degenerate case.

3. Existence analysis.

To check if the equation corresponds to a real or imaginary ellipse, we use the trace invariant:

$$ A + C = 9 + 16 = 25 $$

Since the sign of A + C is different from the sign of δ, the equation corresponds to a real ellipse.

Graph in the Cartesian plane of an ellipse-type conic obtained from the analysis of its general quadratic equation.
Graph of the ellipse-type conic
Find the conic associated with the following general quadratic equation: \( y^2-8x-4y+28=0 \)

Equation analysis


Type: Non-degenerate parabola.

Orientation: Horizontal (principal axis parallel to the x-axis).

Standard form: \( \left(y - 2\right)^2 = 8\left(x - 3\right) \)

For more information about the conic, check the parabola calculator.

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ y^2 - 8x - 4y + 28 = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = 0 \quad B = 0 \quad C = 1 \\[0.5em] D = -8 \quad E = -4 \quad F = 28 $$

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = 0 - 4(0)(1) = 0 $$

Since Δ = 0, the equation corresponds to a general parabola.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(0)(1)(28) - 2(0)(-4)^2 - 2(0)^2(28) + 2(0)(-8)(-4) - 2(1)(-8)^2 \\[0.5em] \delta = -128 $$

Since δ ≠ 0, the equation does not correspond to a degenerate case.

Graph in the Cartesian plane of a parabola-type conic obtained from the analysis of its general quadratic equation.
Graph of the conic section
Identify which conic curve describes the expression \( y^2-x^2-4x+6y-6=0. \)

Equation analysis


Conic section: Non-degenerate hyperbola.

Orientation: Vertical (principal axis parallel to the y-axis).

Standard form: \( \dfrac{\left(y + 3\right)^2}{11} - \dfrac{\left(x + 2\right)^2}{11} = 1 \)

For more information about the conic, check the hyperbola calculator.

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ -x^2 + y^2 - 4x + 6y - 6 = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = -1 \quad B = 0 \quad C = 1 \\[0.5em] D = -4 \quad E = 6 \quad F = -6 $$

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = 0 - 4(-1)(1) = 4 $$

Since Δ > 0, the equation corresponds to a general hyperbola.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(-1)(1)(-6) - 2(-1)(6)^2 - 2(0)^2(-6) + 2(0)(-4)(6) - 2(1)(-4)^2 \\[0.5em] \delta = 88 $$

Since δ ≠ 0, the equation does not correspond to a degenerate case.

Graph in the Cartesian plane of a hyperbola-type conic obtained from the analysis of its general equation.
Graph of the hyperbola
Classify the conic whose general equation is \( 5x^2+4xy+2y^2-24=0. \)

Equation analysis


Classification: Non-degenerate ellipse.

Orientation: Rotated with respect to the Cartesian axes.

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ 5x^2 + 4xy + 2y^2 - 24 = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = 5 \quad B = 4 \quad C = 2 \\[0.5em] D = 0 \quad E = 0 \quad F = -24 $$

Since B ≠ 0, the principal axis of the conic has a rotation with respect to the Cartesian axes.

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = (4)^2 - 4(5)(2) = -24 $$

Since Δ < 0, the equation corresponds to a general ellipse.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(5)(2)(-24) - 2(5)(0)^2 - 2(4)^2(-24) + 2(4)(0)(0) - 2(2)(0)^2 \\[0.5em] \delta = -1152 $$

Since δ ≠ 0, the equation does not correspond to a degenerate case.

3. Existence analysis.

To check if the equation corresponds to a real or imaginary ellipse, we use the trace invariant:

$$ A + C = 5 + 2 = 7 $$

Since the sign of A + C is different from the sign of δ, the equation corresponds to a real ellipse.

Graph in the Cartesian plane of an ellipse-type conic rotated with respect to the Cartesian axes, obtained from the invariant analysis of its general quadratic equation.
Graph of the rotated ellipse
Given the quadratic equation \( xy=4 \), determine what type of conic it is.

Equation analysis


Classification: Non-degenerate hyperbola.

Orientation: Rotated with respect to the Cartesian axes.

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ xy - 4 = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = 0 \quad B = 1 \quad C = 0 \\[0.5em] D = 0 \quad E = 0 \quad F = -4 $$

Since B ≠ 0, the principal axis of the hyperbola has a rotation with respect to the Cartesian axes.

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = (1)^2 - 4(0)(0) = 1 $$

Since Δ > 0, the equation corresponds to a general hyperbola.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(0)(0)(-4) - 2(0)(0)^2 - 2(1)^2(-4) + 2(1)(0)(0) - 2(0)(0)^2 \\[0.5em] \delta = 8 $$

Since δ ≠ 0, the equation does not correspond to a degenerate case.

Graph in the Cartesian plane of a hyperbola-type conic rotated with respect to the Cartesian axes, obtained from the analysis of its general quadratic equation and invariants.
Graph of the rotated hyperbola
Analyze the equation \( x^2-2xy+y^2-8x=0 \) and find what type of conic it represents.

Equation analysis


Classification: Non-degenerate parabola.

Orientation: Rotated with respect to the Cartesian axes.

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ x^2 - 2xy + y^2 - 8x = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = 1 \quad B = -2 \quad C = 1 \\[0.5em] D = -8 \quad E = 0 \quad F = 0 $$

Since B ≠ 0, the principal axis of the parabola has a rotation with respect to the Cartesian axes.

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = (-2)^2 - 4(1)(1) = 0 $$

Since Δ = 0, the equation corresponds to a general parabola.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(1)(1)(0) - 2(1)(0)^2 - 2(-2)^2(0) + 2(-2)(-8)(0) - 2(1)(-8)^2 \\[0.5em] \delta = -128 $$

Since δ ≠ 0, the equation does not correspond to a degenerate case.

Graph in the Cartesian plane of a parabola-type conic rotated with respect to the Cartesian axes, obtained from the analysis of its general quadratic equation and invariants.
Graph of the rotated parabola
Determine the conic corresponding to the general equation \( x^2+y^2=0 \) and whether it is a degenerate case or not.

Equation analysis


Classification: Degenerate ellipse (a real point).

Step-by-step solution

1. Analysis of the conic type.

The given equation is:

$$ x^2 + y^2 = 0 $$

The general equation of a conic is:

$$ Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0 $$

By comparing, we extract the coefficients:

$$ A = 1 \quad B = 0 \quad C = 1 \\[0.5em] D = 0 \quad E = 0 \quad F = 0 $$

We use the discriminant to analyze the conic type:

$$ \Delta = B^2 - 4AC \\[0.5em] \Delta = 0 - 4(1)(1) = -4 $$

Since Δ < 0, the equation corresponds to a general ellipse.

2. Determinant analysis.

To check if the equation corresponds to a degenerate case, we calculate the following determinant:

$$ \delta = \begin{vmatrix} 2A & B & D \\ B & 2C & E \\ D & E & 2F \end{vmatrix} \\[0.5em] \delta = 8ACF - 2AE^2 - 2B^2F + 2BDE - 2CD^2 \\[0.5em] \delta = 8(1)(1)(0) - 2(1)(0)^2 - 2(0)^2(0) + 2(0)(0)(0) - 2(1)(0)^2 \\[0.5em] \delta = 0 $$

Since δ = 0, the equation corresponds to a degenerate case. In this case, the ellipse is just a point.

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Daniel Machado

Professor of Mathematics, graduated from the Faculty of Exact, Chemical and Natural Sciences of the National University of Misiones (UNAM). Developer and creator of RigelUp, dedicated to building tools for mathematical learning.

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