A derivative made from two points.
Two function evaluations define a secant line. Where that line crosses the x-axis becomes the next approximation, and the newest two points define the next secant.
Root finding · CMNA Laboratory
Estimate the slope from the curve itself.
The secant method keeps Newton's x-axis intercept idea but replaces the derivative with a chord through two recent function values.
Bring your own function
One R function. No derivative.
Play the successive chords and watch their x-intercepts become new guesses.
Runtime
Preparing R…RDefine
f| n | previous x | current x | f(current) | next x |
|---|
Book§6.1.3 · Secant Method · p. 173Book details
TeachingInstructor notes and chapter contextOpen teaching material
Numerical ZooWorked problems