How this calculation works
Compute the x-intercept of the secant through two sampled points.
THE FORMULA
xₙ₊₁ = xₙ − f(xₙ)(xₙ−xₙ₋₁)/[f(xₙ)−f(xₙ₋₁)]A worked example
The line through (1,−1) and (2,2) crosses the x-axis at 4/3.
Good to know
A single step supplies an estimate. It may move outside the two sampled x-values.
Reference: OpenStax Algebra and Trigonometry (opens in a new tab) ↗
Read the result
Compute the x-intercept of the secant through two sampled points.
The primary result is labeled “Next root estimate”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
A single step supplies an estimate. It may move outside the two sampled x-values.
For a related exercise, try the quadratic equation solver.
A few questions, answered
How can I check the default inputs by hand?
The line through (1,−1) and (2,2) crosses the x-axis at 4/3.
Which rule does this calculator apply?
xₙ₊₁ = xₙ − f(xₙ)(xₙ−xₙ₋₁)/[f(xₙ)−f(xₙ₋₁)]