4. Given the equation r3 + 4r2- 10-0 (a) (2 marks) Use the Matlab built-in function to find all roots of the above equation. (b) (8 marks) Use Matlab to perform 20 iterations of the fixed point method for each of the following functions, starting with po 1.5, and a tolerance of 10-5. In the case of convergence, mention the number of iterations when the convergence is acnieved. () gi(z) = x-2.3-4x2 + 10 3 1/2 10 1/2 (iii) gs(x) 10 (iv) a(z) = 4. Given the equation r3 + 4r2- 10-0 (a) (2 marks) Use the Matlab built-in function to find all roots of the above equation. (b) (8 marks) Use Matlab to perform 20 iterations of the fixed point method for each of the following functions, starting with po 1.5, and a tolerance of 10-5. In the case of convergence, mention the number of iterations when the convergence is acnieved. () gi(z) = x-2.3-4x2 + 10 3 1/2 10 1/2 (iii) gs(x) 10 (iv) a(z) =