i have a problem with this recurrence relation. I have to find the Theta notation. I tried to solve it with the iterative method. The generic formula I calculated is: T(n)=T[(4/5)^k n]+[(4/5)^(k+1) n]^2+[(4/5)^(k+2) n]^2+⋯+n^2
n=4/5^k -> k= log in base 4/5 of n.
At this point I tried to calculate the geometric series, forgetting the square elevation.. I don't know ho to continue.
Thanks for your attention.