Secant method is given by

df = (f(i+1) - f(i))/(x(i+1)-x(i)); x(i+2) = x(i+1) - f(i+1)/df; 

A MATLAB Script (with bug), using the 'for-loop', to compute the root of f(x) = x^4 - 8 is given by

 x1 = -2; f1=x1^4-16; x2 = 3; f2=x2^4-16; n=3; for i=1:n df=(f2 + x1)*(x1-f1); x3=x1 + x2/df; f3=x3*4-16; disp([i x1 x2 x3]) x1=x2; x2=x3; f1=f2; f2=f3; end 

(a) Fix the bug and write the correct code. (b) What is the value of the root closest to at 8 iteration?