UTILS.
100% in-browser
🧮

Taylor / Maclaurin Series Calculator

Expand f(x) as a Taylor series about a point a (Maclaurin when a = 0) up to n terms, showing each derivative, coefficient and the polynomial.

Enter f(x), a center point, and how many terms. Center 0 gives a Maclaurin series.

About this tool

The Taylor / Maclaurin Series Calculator is a free, in-browser calculus tool that expands a function f(x) as a power series about a center point a. When a = 0 this is the Maclaurin series. It uses the same symbolic differentiation engine as the Derivative tool to compute successive derivatives f, f', f'', … and evaluates each one at the center to build the coefficients cₖ = f⁽ᵏ⁾(a) / k!, forming the polynomial Pₙ(x) = Σ cₖ·(x − a)ᵏ.

Everything runs locally in your browser, so nothing you enter is uploaded. Choose the center a (default 0) and the number of terms n, and the calculator returns the simplified Taylor polynomial in ascending powers together with a term-by-term table listing k, the k-th derivative value f⁽ᵏ⁾(a), and its coefficient cₖ. The factorial in each denominator is computed iteratively. You can type the usual operators, ^ for powers, parentheses, the constants pi and e, and functions like sin, cos, exp, ln and sqrt.

Familiar expansions come straight out: exp(x) about 0 gives 1 + x + x²/2 + x³/6 + …, sin(x) gives x − x³/6 + x⁵/120 − …, and 1/(1 − x) gives 1 + x + x² + …. If the function or one of its derivatives is undefined at the chosen center (for instance ln(x) at a = 0), the tool reports invalid input, since the series cannot be built there. This mirrors the Taylor-series pages of Symbolab and eMathHelp.

Frequently asked questions

What is the difference between Taylor and Maclaurin?
A Maclaurin series is just a Taylor series centered at a = 0. Set the center to 0 and you get the Maclaurin expansion; set it to any other value a and you get the general Taylor series in powers of (x − a).
How are the coefficients computed?
The tool differentiates f symbolically to get f, f', f'', …, evaluates each derivative at the center a, and divides by the factorial k! to form cₖ = f⁽ᵏ⁾(a)/k!. Each term is cₖ·(x − a)ᵏ and they are summed into the polynomial.
How many terms should I use?
The number of terms n controls how many powers appear, from the constant term up to degree n − 1. More terms give a closer approximation near the center but a longer polynomial; 5 to 8 terms is typical for illustrating a series.
Why do I get invalid input for ln(x) at 0?
ln(x) and its derivatives blow up at x = 0, so a Maclaurin series there does not exist. Pick a center inside the function's domain — for example expand ln(x) about a = 1 — and the calculator produces the series.

More tools