I am trying to solve this Recurrence Equation and convert it into big O notation using substitution T(n) = T(n/2) + c

So...

I calculated:

Now I'm lost. Some resources talk of setting n - k = 0 but I don't see how this can help and why you can do this?Code:T(n) = T(n/4) + 2c T(n) = T(n/8) + 3c T(n) = T(n/2^k) + kc