Cartesian to Polar Equation Calculator

Transform Cartesian equations into polar equations quickly. Review substitutions, solved forms, sample points, and exports. Use clear steps for accurate maths practice workflows today.

Calculator

Use the general Cartesian form:

Ax² + Bxy + Cy² + Dx + Ey + F = 0

Formula Used

The calculator starts with this Cartesian equation:

Ax² + Bxy + Cy² + Dx + Ey + F = 0

It applies these polar substitutions:

x = r cosθ

y = r sinθ

The grouped polar form becomes:

r²(Acos²θ + Bsinθcosθ + Csin²θ) + r(Dcosθ + Esinθ) + F = 0

When possible, the equation can be solved as a quadratic in r.

How to Use This Calculator

  1. Write your equation in the form Ax² + Bxy + Cy² + Dx + Ey + F = 0.
  2. Enter zero for any missing coefficient.
  3. Choose a sample angle for numerical checking.
  4. Select degrees or radians.
  5. Choose the decimal precision.
  6. Press calculate to view the polar equation above the form.
  7. Use CSV or PDF export for saving the result.

Example Data Table

Example Cartesian Equation A B C D E F Expected Polar Form
Circle through origin x² + y² - 4x = 0 1 0 1 -4 0 0 r = 4cosθ
Horizontal line y - 3 = 0 0 0 0 0 1 -3 r = 3 / sinθ
Vertical line x - 5 = 0 0 0 0 1 0 -5 r = 5 / cosθ
Rotated curve x² + 2xy + y² - 6 = 0 1 2 1 0 0 -6 r²(cosθ + sinθ)² = 6

About This Calculator

A Cartesian equation describes a curve with x and y. A polar equation describes the same curve with r and θ. This calculator changes the form by using standard substitutions. It accepts a full second degree equation. That means it can handle lines, circles, parabolas, ellipses, hyperbolas, and many rotated forms.

Why Polar Form Helps

Polar form is useful when distance and direction matter. Many curves look simpler from an origin point. Circles through the origin often become short polar equations. Lines also convert neatly when written as r times a trigonometric expression. This makes graphing easier for many maths problems.

What The Tool Calculates

The calculator replaces x with r cos θ. It replaces y with r sin θ. Then it groups the equation by powers of r. The grouped result shows a quadratic style equation in r. When possible, the tool also gives a solved form for r. It checks a sample angle and reports possible radius values. This helps verify the conversion.

How To Read The Result

The first result line shows the original Cartesian equation. The next line shows the substituted polar equation. The compact line groups terms as r squared, r, and the constant. If the equation is linear, the solved form is usually direct. If it is quadratic, two branches may appear. A branch may be invalid when the discriminant is negative.

Good Input Practice

Enter zero for missing terms. Use decimals when needed. Keep signs with the coefficient. For example, use -4 for a negative x term. Select a precision that fits your work. Use degrees for classroom angles. Use radians for advanced calculus or physics work.

Practical Use Cases

Students can check homework steps. Teachers can prepare examples quickly. Designers can review radial patterns. Engineers can compare coordinate models. The export buttons help save work for notes, records, or reports. Always compare the result with a graph when accuracy matters.

Accuracy Notes

A conversion does not change the curve. It changes the language used to describe it. Some solved polar forms may have restrictions. Denominators cannot be zero. Square roots need nonnegative values. Review the notes before using values in proofs, or classroom worksheets and final written exams today.

FAQs

What is a Cartesian to polar equation conversion?

It rewrites an equation using r and θ instead of x and y. The curve stays the same, but the coordinate language changes.

Which substitutions are used?

The calculator uses x = r cosθ and y = r sinθ. It then simplifies and groups the equation by powers of r.

Can this calculator handle xy terms?

Yes. Enter the B coefficient for the xy term. The result includes the polar term Br²sinθcosθ.

What should I enter for a missing term?

Enter zero. For example, if the equation has no xy term, set B to 0.

Why are there two r values sometimes?

Some converted equations become quadratic in r. A quadratic equation can have two branches, one branch, or no real branch.

Does the calculator simplify every trigonometric identity?

It performs the main coordinate substitution and grouping. Some special identities may still need manual simplification for a final classroom style answer.

Why is the sample angle useful?

It checks the converted equation numerically. This helps confirm possible radius values at a chosen direction.

Can I save my result?

Yes. Use the CSV button for spreadsheet data. Use the PDF button for a printable result summary.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.