Solve the following stiff initial-value problem using the Runge-Kutta fourth-order method with (a) h = 0.1 and

Question:

Solve the following stiff initial-value problem using the Runge-Kutta fourth-order method with (a) h = 0.1 and
(b) h = 0.025.
u'1 = 32u1 + 66u2 + 2/3 t + 2/3 , 0≤ t ≤ 0.5, u1(0) = 1/3;
u'2 = −66u1 − 133u2 - 1/3t - 1/3 , 0≤ t ≤ 0.5, u2(0) = 1/3.