Solve the Recurrence using any method which can solve it quickly in less steps

Question

Solve the Recurrence using any method

T(n)=2 T ($\frac{n}{4}$ ) - n2

Answer 1

yes, we cant apply masters on -ve sign..

Comments

So dear Sir now please tell

Answer 2

Check Master's Method Here : https://www.youtube.com/watch?v=lPUhHmgrpik

Comments

I showed this answer to my Phd teacher she said no we cannot solve with negative sign using Master Theorem.

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somebody please tell how to solve it now ?? we cant apply masters.

now using other method how can we solve please tell it is very confusing please tell please?

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Where is the video please tell me ??

Answer 3

Using Substitution method, T(n) = O(n²).

Decreasing GP: Solving gives approximately 1 because the (common ratio)^log n  gets subtracted from 1 and common ratio < 1 . for larger values of log n, (common ratio)^{log n} = 0. There are log n terms in this GP.

If you ask me O(-n²) is same as O(n²).

Visit this link : https://www.quora.com/Is-it-theoretically-possible-for-an-algorithm-to-have-negative-complexity

ps: Sorry for cutting and clarity :)