Bisection root finder
Keep the root bracketed.
Open calculatorMathematics / Free calculator
Polynomial interpolation
Evaluate the Newton or Lagrange interpolating polynomial through 2–10 supplied points.
01 Your inputs
02 Your result
Enter your values and select Calculate.
The method
A worked example
The points (0, 1), (1, 2), and (2, 5) lie on P(x) = x² + 1. Both methods give P(1.5) = 3.25 and reproduce each node.
Assumptions & limits
Floating-point polynomial interpolation, not regression or a smoothing spline. Distinct x values are required. High degree, clustered nodes, and large coordinate offsets can be ill-conditioned; rescale and independently verify. Extrapolation is explicitly warned. A tiny residual at the supplied nodes does not guarantee accuracy between them. Full double precision between operations; displayed values use up to 10 decimal places. Numerical outputs above 10¹⁰⁰ and nonfinite function evaluations are rejected.
Calculation source: Math Workbench: Newton and Lagrange interpolation.