Partial fraction decomposition calculator

Calculate residues matching denominator-root order and direct rational value at check x with your own figures.

Your numbers

Use the units shown. Results update as you change valid inputs.

Use residues matching denominator-root order and direct rational value at check x to compare changes to your inputs. The method and limits below explain the scope.

Examples

Examples

Try the starting example

Proper numerator coefficients, highest degree first
1
Distinct real roots of monic denominator
-1,1
Check x away from poles
2
Residues matching denominator-root order
-0.5, 0.5
Direct rational value at check x
0.333333
Partial-fraction reconstruction at check x
0.333333
Absolute reconstruction difference
0

Try another scenario

Proper numerator coefficients, highest degree first
2,1
Distinct real roots of monic denominator
-1,1
Check x away from poles
0
Residues matching denominator-root order
0.5, 1.5
Direct rational value at check x
-1
Partial-fraction reconstruction at check x
-1
Absolute reconstruction difference
0
Calculation method

Calculation method

Residues matching denominator-root order

For a simple real pole r_i, residue=P(r_i)/product(r_i−r_j for j≠i). Denominator is product(x−r_i).

Direct rational value at check x

P(x) divided by the supplied monic factored denominator.

Partial-fraction reconstruction at check x

Sum residue_i/(x−r_i).

Absolute reconstruction difference

Absolute difference between direct and reconstructed values.

Symbols and units
a
Proper numerator coefficients, highest degree first
b
Distinct real roots of monic denominator
c
Check x away from poles

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions & limits

Assumptions & limits

  • Supports proper rational functions with distinct real linear denominator factors, up to 12 poles. Repeated or irreducible quadratic factors are outside this explicitly supported factor type. Double-precision results are approximate. Numeric tables use 12 significant digits and display components at roundoff scale (32 machine epsilons relative to their row or relevant calculation scale) as zero; scalar diagnostics retain full precision.
Are these inputs private?

These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.

Further reading

OpenStax: partial fractions ↗

Background reading; this does not imply endorsement or independent review of SumFizz.

Share this page
Share this calculator

Leave unchecked to share the page without your entered values.