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Let \(T f : \mathbb {N} \rightarrow \mathbb {N}\) be functions such that the recurrence
holds for some \(a {\gt} 0\) and \(b {\gt} 1\). Let also \(f(n) \in \Theta (n^d)\) for some \(d \ge 1\). Then the following holds:
if \(a {\lt} b^d\), then \(T(n) \in \Theta (n^d)\),
if \(a = b^d\), then \(T(n) \in \Theta (n^d \log _b{n})\) and
if \(a {\gt} b^d\), then \(T(n) \in \Theta (n^{\log _b{a}})\).
In the case where \(f\) is bounded above by \(n^d\) only above or only below, \(T\) is also bounded only above or only below by the respective function.
Let \(T f : \mathbb {N} \rightarrow \mathbb {N}\) be functions such that \(T\) is monotone and the recurrence
holds for all \(n \ge n\_ 0\) for some \(a {\gt} 0\), \(n\_ 0 {\gt} 1\) and \(b {\gt} n\_ 0\). Let also \(f(n) \in \Omega (n^d)\) for some \(d \ge 1\). The above recurrence is a lower master recurrence with parameters \((a, n\_ 0, b, d)\).
Let \(T f : \mathbb {N} \rightarrow \mathbb {N}\) be functions such that \(T\) is monotone and the recurrence
holds for all \(n \ge n\_ 0\) for some \(a {\gt} 0\), \(n\_ 0 {\gt} 1\) and \(b {\gt} n\_ 0\). Let also \(f(n) \in O(n^d)\) for some \(d \ge 1\). The above recurrence is an upper master recurrence with parameters \((a, n\_ 0, b, d)\).