Use the substitution method to prove the running time of the following recurrence is O(n^3) Use the substitution method to prove the running time of the following recurrence is O(n^3). T(n) = 2T(n/2) + n^3 Solution solution T(n)=2T(n/2)+n^3 we will compare it with T(n)=aT(n/b)+f(n) so we get, a=2, b=2, f(n)= n^3 As per Master Theorem we have, T(n)= O(n^3).