Probe $\lim_{{x \to a}} f(x)$ or behavior as $x \to \pm\infty$ by evaluating a constrained expression at a ladder of nearby points. Allowed pieces match the derivative tool: numbers, x, + - * / ^, parentheses, and sin cos tan sqrt abs log exp pi e.
Numerical limit estimator
What it computes. A sampling-based estimate with left/right (or large-$|x|$) probes — useful for intuition, not a formal $\varepsilon$-$\delta$ proof.
Limitations. Removable holes, oscillations, and vertical asymptotes can fool any finite sample. See the disclaimer.
Related: Epsilon-delta intuition · Limit · Calculus foundations · Numerical derivative