matlab关于二分法的例题:sinx+x+1=o在定义域的根,精确到10的-6次方

function erfenfa()
close all;clear all; clc;
lim_a = -1;
lim_b = 1;
error = 1;
if fun(lim_a)*fun(lim_b)>0
disp(['在所给范围内无解']);
else
if fun(lim_a)==0
result = lim_a; error = 0;
end
if fun(lim_b)==0
result = lim_b; error = 0;
end
while error > 1e-6
mid = (lim_a+lim_b)/2;
if fun(mid)*fun(lim_a)