I can't figure out a working function to use Newton Raphson to approximate arctan(x). I am using f = arctan(x) and df = 1/(1+x^2), and it just keeps converging to 0 or diverging to infinity. Here's the prototype: function [y,terms] = invtanNR( x, tol, numTerms) % [y,terms] = invtanNR(x, tol, numTerms) % % Finds arctan of the number x using NR % using either MaxTerms passes or % having a relative step size < Tolerance % relative step size = abs( yOld y ) / abs( y ) % % input: % x Find arctan of this number % tol Step size % numTerms Max number of terms to use ( 500 ) % % output: % y our resultant (arctan(x)) % terms num of terms %