Problem 4: Use while loop to calculate the sum of the series with a convergence error of 0.0001 Create a graph of the cumulative sum versus number of iterations Problem 5: Find the value of f a1/3 In(t(D - d)) +et t=0.5 +log10 where a=1 b=8 D = 2d d=5 Problem 6: Use MATLAB ode45 function to plot the solution of the 2nd order ODE for the values of t = [0, 2]: 20.. + 400y = 0 d2 dt2 dt