Need help on some MATLAB code-problem solving with an initial value problem.

You will like to solve the problem y = sin(t) + g(y), y(0) = 6, up to a final time t_f = 4. Here, g(y) is the solution of 2z = e^-z^2 + |sin(y)|z^1/3. For example, if y = pi/2, then g(y) is the solution of 2z = e^-z^2 + |sin(pi/2)| z^1/3, (i.e., g(pi/2) almostequalto 0.74115995). Use your fourth-order Runge-Kutta code in conjunction with some sort of fixed-point code - which you should write as a separate function. Plot your approximate solution for the following values of n, n elementof {4, 8, 16, 32, 64, 128, 256)