need check for Bisection Method

%bisection_method

f='func31'

Nmax=100;

tol=0.000001;

a=-10

b=10

if feval(f,a)*feval(f,b)>0

disp('no sol')

else

a0=a; b0=b;

for n=1:Nmax

p=(a+b)/2

if (b-p)/(b0-a0)<tol <------------------------------------------------------------is this right?? b-p? not a b-a?

break

else

if feval(f,a)*feval(f,p)<=0

a=a;

b=p;

else

a=p

b=b

end

end

end

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made an expression from relative error

i wrote it down at the class

but there are difference with books

is it

b-p or b-a?

Answer 1

[Alan Stevens]

When you are close to the solution it won't much matter if you use b-p or b-a. However, you shoud probably use

abs((b-p)/(b0-a0))<tol 

[pepper]

thanks!