Limit lim x→a f(x) Calculator

Evaluate lim x→a f(x) for a function you type, including limits at infinity (enter inf or -inf for a).

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What it asks for

The formula

limx→a f(x) = L

From the article Limits — The Idea Behind lim x→a f(x).

Worked example

Evaluate limx→3 (x² − 9) / (x² − x − 6).

Step 1 — check the form. Numerator at x = 3: 9 − 9 = 0. Denominator at x = 3: 9 − 3 − 6 = 0. So it is 0/0 — indeterminate, work needed.

Step 2 — factorise both.
x² − 9 = (x − 3)(x + 3)
x² − x − 6 = (x − 3)(x + 2)

Step 3 — cancel (x − 3). This is legal because x ≠ 3 inside the limit — x only approaches 3. Write that line down; examiners look for it.

= limx→3 (x + 3)/(x + 2) = (3 + 3)/(3 + 2) = 6/5 = 1.2

Check at x = 3.001: 0.006001 / 0.005001 = 1.19996 ✔

Worked in full in Limits — The Idea Behind lim x→a f(x).

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About this tool

This is one of the tools in the Chemistry Calculator Suite, a free calculator built for IIT-JAM, CSIR-NET, GATE and CUET (Chemical Science) preparation. Nothing is behind a login and no result is stored on a server — the arithmetic runs in your own browser.

The Limit lim x→a f(x) calculator above is the live tool — type your values and press its button; the answer appears in the same box. The link under it opens the full suite with this tool already selected, next to the others.

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