Conic Sections Calculator

Analyze circles, parabolas, ellipses, and hyperbolas with step-by-step solutions and interactive graphs.

Enter an equation or properties and click "Calculate" to analyze the conic section.

Parameters

Standard Form

Graph

Graph will appear here after calculation

Step-by-step solution will appear here after calculation.

Conic Sections Guide

A circle is the set of all points in a plane that are equidistant from a fixed point (the center).

Standard Form: \((x - h)^2 + (y - k)^2 = r^2\)

Where \((h, k)\) is the center and \(r\) is the radius.

General Form: \(x^2 + y^2 + Dx + Ey + F = 0\)

A parabola is the set of all points equidistant from a fixed point (the focus) and a fixed line (the directrix).

Standard Forms:

  • Vertical: \((x - h)^2 = 4p(y - k)\)
  • Horizontal: \((y - k)^2 = 4p(x - h)\)

Where \((h, k)\) is the vertex and \(p\) is the distance from vertex to focus.

An ellipse is the set of all points where the sum of distances to two fixed points (foci) is constant.

Standard Forms:

  • Horizontal major axis: \(\frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} = 1\)
  • Vertical major axis: \(\frac{(x-h)^2}{b^2} + \frac{(y-k)^2}{a^2} = 1\)

Where \((h, k)\) is the center, \(a\) is semi-major axis, \(b\) is semi-minor axis.

A hyperbola is the set of all points where the difference of distances to two fixed points (foci) is constant.

Standard Forms:

  • Horizontal transverse axis: \(\frac{(x-h)^2}{a^2} - \frac{(y-k)^2}{b^2} = 1\)
  • Vertical transverse axis: \(\frac{(y-k)^2}{a^2} - \frac{(x-h)^2}{b^2} = 1\)

Where \((h, k)\) is the center, \(a\) is distance from center to vertex.

Educational Guide to Conic Sections

This calculator analyzes four types of conic sections:

  • Circles: All points equidistant from a center point
  • Parabolas: Points equidistant from a focus and directrix line
  • Ellipses: Points where sum of distances to two foci is constant
  • Hyperbolas: Points where difference of distances to two foci is constant

The tool identifies the conic type from your input, converts it to standard form, calculates all key parameters, and provides visual representation.

Conic Sections are curves formed by intersecting a plane with a double-napped cone. The angle of intersection determines the curve type:

  • Circle: Plane cuts parallel to base of cone
  • Ellipse: Plane cuts at angle less steep than side of cone
  • Parabola: Plane cuts parallel to side of cone
  • Hyperbola: Plane cuts steeper than side of cone

All conics can be described by second-degree polynomial equations in x and y. The relationship between coefficients determines which conic you have.

Standard Form Inputs:
  • h, k: Coordinates of center (circle, ellipse, hyperbola) or vertex (parabola)
  • r: Radius of circle - distance from center to any point on circle
  • a: Semi-major axis (ellipse) or distance from center to vertex (hyperbola)
  • b: Semi-minor axis (ellipse) or conjugate axis parameter (hyperbola)
  • p: Distance from vertex to focus (parabola)
General Form Coefficients (Ax² + Bxy + Cy² + Dx + Ey + F = 0):
  • A, C: Coefficients of x² and y² terms - their relationship determines conic type
  • B: Coefficient of xy term - indicates rotation of conic
  • D, E: Linear term coefficients - affect center/vertex position
  • F: Constant term

Circle: (x - h)² + (y - k)² = r²

"For any point (x, y) on the circle, the squared horizontal distance (x-h)² plus the squared vertical distance (y-k)² equals the squared radius r²." This is essentially the Pythagorean theorem applied to distances from the center.

Parabola: (x - h)² = 4p(y - k)

"The squared horizontal distance from the vertex equals 4 times p times the vertical distance from the vertex." The value p determines how "wide" or "narrow" the parabola opens.

Ellipse: (x-h)²/a² + (y-k)²/b² = 1

"The squared horizontal distance divided by a² plus the squared vertical distance divided by b² equals 1." The larger denominator (a or b) tells you which direction the ellipse is stretched.

Hyperbola: (x-h)²/a² - (y-k)²/b² = 1

"The squared horizontal distance divided by a² minus the squared vertical distance divided by b² equals 1." The minus sign creates the two separate branches of the hyperbola.

  1. Input Recognition: The calculator identifies which conic type you're working with based on your input format.
  2. Equation Parsing: For general form, it extracts coefficients A, B, C, D, E, F from your equation.
  3. Conic Classification: Using discriminant B² - 4AC:
    • B² - 4AC < 0: Ellipse (or circle if A = C and B = 0)
    • B² - 4AC = 0: Parabola
    • B² - 4AC > 0: Hyperbola
  4. Completing the Square: For circles, ellipses, and hyperbolas, it groups x-terms and y-terms separately, then adds constants to create perfect squares.
  5. Standard Form Conversion: Rearranges the equation into the recognizable standard form.
  6. Parameter Calculation: Computes all geometric parameters (center, radii, foci, vertices, etc.) from the standard form.
  7. Graph Plotting: Uses parametric equations or explicit functions to plot points along the curve.

Key Parameters to Understand:
  • Center/Vertex: The "anchor point" of the conic - all other measurements relate to this point.
  • Radius/Axes: Measure the size of the conic. For ellipses, a is always ≥ b.
  • Foci (plural of focus): Special points that define ellipses and hyperbolas. For parabolas, there's only one focus.
  • Eccentricity (e): Measures how "stretched" the conic is:
    • Circle: e = 0
    • Ellipse: 0 < e < 1
    • Parabola: e = 1
    • Hyperbola: e > 1
  • Directrix: A fixed line used with focus to define parabolas.
  • Asymptotes: Lines that hyperbola branches approach but never touch.

Tip: Compare your calculated values with the graph to build intuition about what each parameter represents visually.

Circles:
  • Wheels, gears, and circular motion
  • Satellite orbits (circular orbits)
  • Roundabouts and circular architecture
Ellipses:
  • Planetary orbits (Kepler's first law)
  • Whispering galleries - sound reflects from one focus to another
  • Elliptical gears and machine components
  • Satellite dish design (some types)
Parabolas:
  • Satellite dishes and parabolic reflectors
  • Headlight and flashlight reflectors
  • Suspension bridge cables
  • Projectile motion (ignoring air resistance)
Hyperbolas:
  • Navigation systems (LORAN, GPS)
  • Cooling tower designs
  • Sonic booms (shock wave front)
  • Some telescope and antenna designs

Input Errors:
  • Sign errors: Forgetting that (x - h) means h is subtracted, so if center is at (2, -3), the equation has (x - 2) and (y + 3)
  • Square root confusion: In circles, if r² = 25, then r = 5 (not r = 25)
  • Axis confusion: For ellipses, a is always the semi-major axis (larger), b is semi-minor (smaller)
  • Parabola p-value: Remember p is distance from vertex to focus, so 4p appears in the equation
Conceptual Errors:
  • Circle vs. ellipse: A circle is a special ellipse where a = b, but the formulas are different
  • Hyperbola asymptotes: The asymptotes go through the center, not the origin (unless center is at origin)
  • Parabola orientation: The squared term tells you which way it opens:
    • (x-h)² = opens up/down
    • (y-k)² = opens left/right
  • Foci positions: For ellipses, foci are inside the ellipse along major axis. For hyperbolas, foci are outside between branches.

Coordinate System:
  • This calculator uses the standard Cartesian coordinate system (x-axis horizontal, y-axis vertical)
  • All measurements are in consistent units - if you input radius as 5, it means 5 units
  • The graph scale shows unitless numbers - interpret based on your input values
Important Considerations:
  • Consistency: All measurements must use the same units
  • Scale: The graph automatically scales to show the entire conic - use zoom controls to see details
  • Aspect ratio: The graph maintains equal scaling on both axes (1:1 aspect ratio) to preserve geometric accuracy
  • Negative values: All parameters can be negative except radii and axis lengths (a, b, r), which are always positive

Real-world conversion: If working with real measurements (meters, feet, etc.), ensure all inputs use the same unit. The calculator doesn't convert between units.

Calculation Precision:
  • Internal calculations use JavaScript's double-precision floating point (about 15-17 decimal digits)
  • Displayed results are rounded to 2 decimal places for readability
  • Exact fractions (like π) are approximated: π ≈ 3.141592653589793
  • Square roots and trigonometric functions use built-in JavaScript approximations
When to Expect Rounding Errors:
  • Very large numbers (greater than 10⁹) may lose precision
  • Very small numbers (less than 10⁻⁹) may be treated as zero
  • Equations with coefficients that differ by many orders of magnitude
  • Calculations involving subtraction of nearly equal numbers
Graphical Accuracy:
  • The graph plots discrete points - between points, the curve is interpolated
  • Zoom in to see more detail and verify curve shape
  • Asymptotes on hyperbolas are drawn as lines, but the curve approaches them infinitely close
  • Parabola directrix is shown as a dashed line

Educational note: For exact mathematical work, use symbolic algebra. This tool provides numerical approximations suitable for visualization and understanding.

Effective Learning Strategies:
  1. Start with examples: Use the quick example buttons to see standard forms of each conic
  2. Change one parameter at a time: See how changing radius affects a circle, or how changing p affects a parabola
  3. Compare types: Enter similar equations for different conics and compare their graphs
  4. Verify algebraically: Try the same problem by hand, then check with the calculator
  5. Use step-by-step solutions: Turn on "Show Step-by-Step Solution" to see the algebraic process
Conceptual Understanding:
  • Visualize parameters: On the graph, identify center, vertices, foci, asymptotes
  • Trace the relationship: For ellipses, note that as foci get closer to center, ellipse becomes more circular
  • Understand limits: What happens to an ellipse as a approaches b? (It becomes a circle)
  • Connect forms: Enter general form, see standard form, check that they're equivalent
Problem-Solving Practice:
  • Given a graph, try to determine the equation
  • Work backward: Start with parameters, predict the equation, then verify
  • Create "mystery conics" for classmates to identify
  • Explore degenerate cases: What happens when radius = 0? When a = 0?

Graph Elements:
  • Solid colored curve: The conic section itself
  • Black dots: Key points (center, vertices, foci)
  • Gray grid: Coordinate system with 1-unit spacing
  • Dashed lines: Asymptotes (hyperbolas) or directrix (parabolas)
  • Labels: Coordinates of important points
What to Look For:
  • Circles: Perfectly round, equal distance from center all around
  • Ellipses: Oval shape, symmetric about both axes through center
  • Parabolas: U-shaped (or sideways U), symmetric about axis through vertex and focus
  • Hyperbolas: Two mirror-image curves opening in opposite directions
Using Graph Controls:
  • Zoom In: Examine small details or precise point locations
  • Zoom Out: See the overall shape and asymptotic behavior
  • Reset View: Return to default scale showing entire conic
  • Color change: Helps distinguish multiple curves if comparing

Note: The graph shows mathematical ideals - perfect curves with infinite precision. Real-world applications may have imperfections.

Visual Accessibility:
  • Dark mode: Available via moon icon in options - reduces eye strain
  • Color contrast: Graph uses high-contrast colors against light/dark background
  • Graph labels: All key points are labeled with coordinates
  • Zoom controls: Allow users to enlarge graph details
Navigation and Interaction:
  • Keyboard navigation supported for all controls
  • Clear visual feedback on button clicks and selections
  • Consistent layout and predictable behavior
  • Error messages in plain language
Content Accessibility:
  • Mathematical formulas rendered using MathJax for screen reader compatibility
  • Alternative text descriptions for graphical elements
  • Structured content with clear headings
  • Multiple representation modes: equations, parameters, graphs, steps

Learning diversity support: The tool provides visual, numerical, and algebraic representations simultaneously, supporting different learning styles.

Current Version: January 2026

Core Features:

  • Four conic section types: circle, ellipse, parabola, hyperbola
  • Three input methods: general form, standard form, geometric properties
  • Interactive graphing with zoom and pan controls
  • Step-by-step algebraic solutions
  • Parameter calculation and display
  • Export to PDF and image formats
  • Dark/light mode toggle
Mathematical Capabilities:
  • General form equation parsing and classification
  • Completing the square algorithm
  • Parameter extraction from standard form
  • Geometric property calculations (foci, vertices, asymptotes, etc.)
  • Graph plotting using parametric and explicit equations
Technical Details:
  • Pure client-side JavaScript - no server calculation needed
  • Uses HTML5 Canvas for graphing
  • MathJax integration for mathematical notation
  • Bootstrap 5 for responsive design
  • No external dependencies except CDN libraries

Educational Focus: This version emphasizes clarity, step-by-step explanations, and multiple representation modes to support geometry education.