I need help with the code for 2b. My plot would not generate any thing

Here's what I got:

f=@(x)cos(x)-0.3*x; %function

x1=0;

x2=2;

while (f(x2)-f(x1))/20.001 %ea is relative error

ea=abs((xnew-xold)/xnew)*100;

fnew=f(xnew)

f1=f(x1)

f2=f(x2)

xnew=(x1+x2)/2

if fnew*f1

x2=xnew

else

x1=xnew

end

end

x=[1,1.5,1.25,1.125];

plot(x,ea,'k')

Find the positive solution of the equation cosx=0.3x, using the Bisection method with [0, 2] chosen as the initial interval. (a) Perform the first 4 iterations by hand and calculate the relative error for the last iteration; (b) Write a MATLAB code to find the root. The solution will be considered satisfactory if its relative error is smaller than 1%. Plot the relative error vs the number of iterations