Taylor Series Calculator

Polynomial approximations of functions

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About Taylor Series Calculator

A Taylor series calculator that expands common functions into their polynomial approximations around a center point. Shows each term, partial sums, remainder estimate, and convergence behavior. Supports sin, cos, eˣ, ln(1+x), arctan, and 1/(1−x). All calculations are client-side. Essential for calculus, physics, and numerical methods.

Taylor Series Calculator Features

  • 6 functions
  • n terms
  • Remainder
  • Center point
  • Convergence
Taylor series: f(x) = Σ f⁽ⁿ⁾(a)/n! · (x−a)ⁿ. Maclaurin series: a=0. Key expansions: eˣ = Σxⁿ/n!, sin(x) = Σ(−1)ⁿx²ⁿ⁺¹/(2n+1)!, cos(x) = Σ(−1)ⁿx²ⁿ/(2n)!. The more terms, the better the approximation near the center.

How to Use

Select a function:

  • Function: Choose from presets
  • x value: Where to evaluate
  • Terms: Number of terms

Common Series

  • eˣ = 1 + x + x²/2! + x³/3! + ...
  • sin(x) = x − x³/3! + x⁵/5! − ...
  • cos(x) = 1 − x²/2! + x⁴/4! − ...

Convergence

eˣ, sin, cos converge for all x. ln(1+x) converges for −1 < x ≤ 1. 1/(1−x) converges for |x| < 1.

Step-by-Step Instructions

  1. 1Select a function.
  2. 2Enter x value.
  3. 3Choose number of terms.
  4. 4View term-by-term expansion.
  5. 5Check approximation accuracy.

Taylor Series Calculator — Frequently Asked Questions

What is the difference between Taylor and Maclaurin series?+

Maclaurin series is a Taylor series centered at a=0. Taylor series can be centered at any point a. Maclaurin is just the special case.

Why do some series converge only for certain x?+

Each series has a radius of convergence R. For |x−a| < R, the series converges. Outside, it diverges. The ratio test determines R.

How many terms do I need for a good approximation?+

Depends on x and the function. Near the center, 5-10 terms often suffice. Far from the center, many more are needed (or the series may not converge at all).

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