function [c,err,yc]=regula(f,a,b,delta,epsilon,max1)%Input - f is the function input as a string 'f'%	    - a and b are the left and right endpoints%	    - delta is the tolerance for the zero%	    - epsilon is the tolerance for the value of f at the zero%	    - max1 is the maximum number of iterations%Output - c is the zero%	     - yc=f(c)%	     - err is the error estimate for c%  NUMERICAL METHODS: Matlab Programs% (c) 2004 by John H. Mathews and Kurtis D. Fink%  Complementary Software to accompany the textbook:%  NUMERICAL METHODS: Using Matlab, Fourth Edition%  ISBN: 0-13-065248-2%  Prentice-Hall Pub. Inc.%  One Lake Street%  Upper Saddle River, NJ 07458ya=feval(f,a);yb=feval(f,b);if ya*yb>0	disp('Note: f(a)*f(b) >0'),	break,endfor k=1:max1	dx=yb*(b-a)/(yb-ya);	c=b-dx;	ac=c-a;	yc=feval(f,c);	if yc==0,break;	elseif yb*yc>0		b=c;		yb=yc;	else		a=c;		ya=yc;	end	dx=min(abs(dx),ac);	if abs(dx)<delta,break,end	if abs(yc)<epsilon, break,endendc;err=abs(b-a)/2;yc=feval(f,c);