bisection method error symbolic

hi i'm trying to write a code to solve this question:

the code below need some adjustment to make it work

clear
clc
syms y
q=20;
g=9.8;
b=3+y;
ac=3*y+((y^2)/2);
f=@(y) 1-((q^2)/(g*ac^3)*b);
x1=0.5

x1 = 0.5000

xu=2

xu = 2

ezplot(f(y))
grid on 
hold on

for i=1:100
xr(i)=(x1+xu)/2
if ((f(x1)*f(xr(i)))<0)
    xu=xr(i)
elseif ((f(x1)*f(xr(i))>0))
    x1=xr(i)
    elseif ((f(x1)*f(xr(i))==0))
        break
end
if ((i>1)&&(abs((xr(i)-xr(i-1)))/xr(i-1))*100<0.01)
    break 
end
plot(xr(i),f(xr(i)),'xr')
end

xr = 1.2500

Conversion to logical from sym is not possible.

xr(10)

Answer 1

[Torsten]

syms y
q=20;
g=9.8;
b=3+y;
ac=3*y+y^2/2;
f= 1-q^2/(g*ac^3)*b;
x1=0.5;
xu=2.5;
hold on
fplot(f,[0.5 2.5])
grid on 
f = matlabFunction(f);
for i=1:100
xr(i)=(x1+xu)/2;
if ((f(x1)*f(xr(i)))<0)
    xu=xr(i);
elseif ((f(x1)*f(xr(i))>0))
    x1=xr(i);
    elseif ((f(x1)*f(xr(i))==0))
        break
end
if ((i>1)&&(abs((xr(i)-xr(i-1)))/xr(i-1))*100<0.01);
    break 
end
end
plot(xr,f(xr),'xr')
hold off

[Faisal Al-Wazir]

nice but i did it in another way

clear
clc

q=20;
g=9.8;

syms w
f=@(w) 1-((q^2)/(g*(3*w+((w^2)/2))^3)*(3+w));
f=@(y) 1-((q^2)/(g*(3*y+((y^2)/2))^3)*(3+y));
x1=0.5

x1 = 0.5000

xu=2

xu = 2

ezplot(f(w))
grid on 
hold on
for i=1:10
xr(i)=(x1+xu)/2
if ((f(x1)*f(xr(i)))<0)
    xu=xr(i)
elseif ((f(x1)*f(xr(i))>0))
    x1=xr(i)
    elseif ((f(x1)*f(xr(i))==0))
        break
end
if ((i>1)&&(abs((xr(i)-xr(i-1)))/xr(i-1))*100<0.01)
    break 
end
plot(xr(i),f(xr(i)),'or')
end

xr = 1.2500

x1 = 1.2500

xr = 1×2

1.2500 1.6250

xu = 1.6250

xr = 1×3

1.2500 1.6250 1.4375

x1 = 1.4375

xr = 1×4

1.2500 1.6250 1.4375 1.5312

xu = 1.5313

xr = 1×5

1.2500 1.6250 1.4375 1.5312 1.4844

x1 = 1.4844

xr = 1×6

1.2500 1.6250 1.4375 1.5312 1.4844 1.5078

x1 = 1.5078

xr = 1×7

1.2500 1.6250 1.4375 1.5312 1.4844 1.5078 1.5195

xu = 1.5195

xr = 1×8

1.2500 1.6250 1.4375 1.5312 1.4844 1.5078 1.5195 1.5137

x1 = 1.5137

xr = 1×9

1.2500 1.6250 1.4375 1.5312 1.4844 1.5078 1.5195 1.5137 1.5166

xu = 1.5166

xr = 1×10

1.2500 1.6250 1.4375 1.5312 1.4844 1.5078 1.5195 1.5137 1.5166 1.5151

xu = 1.5151

xr(10)

ans = 1.5151