Bisection Method Coding in Matlab

clc

close all

clear all

syms x % a variable x has been declared by using syms command.

xl=input('lower value=') % taking  lower value from user.

xu=input('upper value=') % taking upper value from user.

a=input('function=') % input function.

f=inline(a) % inline function for declaring variable.

fxl=subs(f,x,xl) % assigning lower value to fxl by using subs command.

fxu=subs(f,x,xu) % assigning upper value to fxu by using subs command.

if(fxl*fxu>0)

    display('error')

else

    for(i=1:10)       % for loop form 1 to 10

        xr=(xl+xu)/2  % for finding mid point of xl and xu

        fxr=subs(f,x,xr) % assigning lower value to fxl by using subs command.

        if(fxl*fxr<0) % if and else command if fxl*fxu less than 0 then

            xu=xr % putting value of xr to xu.

        else

            xl=xr % putting value of xr tp xr

        end

    end

    root=xr % root showing at 10th iteration.

    xnew(i)=xr

    error=xnew(i)-xnew(i-1)

end

   

lower value=1

xl =  1

upper value=2

xu = 2

function=x^6-x-1

a =x^6 - x - 1

f =Inline function:

     f(x) = -x+x.^6-1.0

fxl =-1

fxu =   61

xr =1.5000

fxr =8.8906

xu =  1.500

xr = 1.250

fxr =1.5647

Xu=1.2500

xr =1.1250

fxr = -0.0977

xl = 1.1250

xr = 1.1875

fxr =0.6167

xu = 1.1875

xul= 1.1563

fxr =0.2333

xu =1.1563

xr =1.1406

fxr =0.0616

xu =  1.1406

xr =1.1328

fxr =-0.0196

xl = 1.1328

xr =1.1367

fxr = 0.0206

xu =1.1367

xr =1.1348

fxr = 4.2684e-004

xu =1.1348

xr =  1.1338

fxr = -0.0096

xl = 1.1338

root = 1.1338

xnew = 0         0         0         0         0         0         0         0         0    1.1338

error =1.1338