Maths Tool

Polynomial Substitution Calculator

Substitute values into polynomials with classroom-ready calculations. Track powers, coefficients, derivatives, and Horner evaluation instantly. Save neat outputs for homework, revision, reports, and practice.

Calculator Inputs

Example: 3, -2, 5, -7 represents 3x³ - 2x² + 5x - 7.

Formula Used

General polynomial: \( P(x) = a_nx^n + a_{n-1}x^{n-1} + ... + a_1x + a_0 \)

Substitution: Replace \( x \) with the chosen number \( k \), so \( P(k) = a_nk^n + a_{n-1}k^{n-1} + ... + a_1k + a_0 \).

Horner form: \( (((a_nk + a_{n-1})k + a_{n-2})k + ... )k + a_0 \)

First derivative: \( P'(x) = na_nx^{n-1} + ... + 2a_2x + a_1 \)

Second derivative: \( P''(x) = n(n-1)a_nx^{n-2} + ... + 2a_2 \)

How to Use This Calculator

  1. Enter coefficients from highest power to constant term.
  2. Type the number you want to substitute for the variable.
  3. Choose the variable letter and display precision.
  4. Keep derivative and Horner options checked for deeper analysis.
  5. Press the calculate button to show the result above the form.
  6. Use the export buttons to save a CSV or PDF copy.

Example Data Table

Polynomial Substitution value Result First derivative value
3x³ - 2x² + 5x - 7 x = 2 19 33
2x⁴ + x² - 9 x = -1.5 3.375 -24
-x³ + 4x + 6 x = 3 -9 -23

Frequently Asked Questions

1. What does polynomial substitution mean?

It means replacing the variable in a polynomial with a chosen number, then simplifying every term and adding the results.

2. How should I enter coefficients?

List them from highest degree to constant term. For 4x² - 3x + 8, enter 4, -3, 8.

3. Can I use negative or decimal substitution values?

Yes. The calculator accepts positive, negative, and decimal numbers, then evaluates each power and term accordingly.

4. Why is Horner verification helpful?

Horner form reduces repeated power calculations, checks the same answer efficiently, and is useful for manual verification and programming.

5. What do the derivative results show?

They show how fast the polynomial changes at the substituted value, plus how its curvature behaves through the second derivative.

6. Does the calculator support missing terms?

Yes. Include zero coefficients for missing powers, such as 5, 0, -2 for 5x² - 2.

7. What is shown in the detailed table?

The table lists each power, coefficient, substituted power value, and final term contribution before the polynomial total is summed.

8. Can I export the result for records?

Yes. Use the built-in CSV button for spreadsheet use or the PDF button for a clean printable report.

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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.