用二分法,你得先找出一个根所在的区间 function [a,b]=findbracket(f,x0) %f is the function evaluated %x0 is the starting point %a is the left boundary %b is the right boundary %[a,b] is the interval around x0 wanted a=x0; b=x0; dx=0.001; while f(a)*f(b)>0 a=a-dx; if f(a)*f(b) f=@(x)(x^3)*cos(x)+6*(sin(x))^5-3 f = @(x)(x^3)*cos(x)+6*(sin(x))^5-3 >> [a,b]=findbracket(f,1) a = 0.9850 b = 1.0070 所以在这个区间内有一个根,然后再用二分法精确到0.00001 >> p=bisection(f,a,b,1e-5) p = 0.9919 这是一个根
