Is there a way to do this in a more compact way?

Hello,i have to convert this code as a while loop and also it should be more compact than this form.It includes some hints for convert. Thanks

 % is there a way to do this in a more compact way?

 a=50;
 b=-50;
 for k=0:100 % use while loop
 fa=1-a+sin(a); %*
 fb=1-b+sin(b); %*
  if(fa*fb<0)
      al=a;
      c=(a+b)/2;
      br=b;
      fal=1-al+sin(al); %*
      fc=1-c+sin(c); %*
      fbr=1-br+sin(br); %*
      if(fal*fc<0)
          a=al;
          b=c;
      end
      if(fc*fbr<0)
          a=c;
          b=br;
      end
      if abs(b-a)<10^-4      % integrate this into while loop
          disp([k (b+a)/2]) 
      end      
  end
end