Consider the following functions where n is a positive integer: n1/3, log(n),…
2026
Consider the following functions where n is a positive integer:
n1/3, log(n), log(n!), 2log(n)
Which one of the following lists the functions in increasing order of asymptotic growth rate?
Note: Assume the base of log to be 2.
Answer: A. log(n), n1/3, 2log(n), log(n!) — ConceptAsymptotic growth compares how positive functions scale as n becomes large. Every fixed positive power of n eventually dominates a logarithm, and…
- A.
log(n), n1/3, 2log(n), log(n!)
- B.
n1/3, log(n), log(n!), 2log(n)
- C.
log(n), n1/3, log(n!), 2log(n)
- D.
2log(n), n1/3, log(n), log(n!)
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Show answer & explanation
Correct answer: A
Concept
Asymptotic growth compares how positive functions scale as n becomes large. Every fixed positive power of n eventually dominates a logarithm, and Stirling’s approximation gives log(n!) = Θ(n log(n)).
The stated base matters here: with base 2, 2log₂(n) = n.
Application
A logarithm is dominated by any positive polynomial power, so log2(n) = o(n1/3).
Using the base-2 identity, 2log₂(n) = n. Since n1/3 = o(n), the fractional-power term comes before this exponential-log term.
Stirling’s approximation gives log2(n!) = Θ(n log₂(n)). Therefore n = o(log₂(n!)).
Cross-check
log₂(n) / n1/3 → 0.
n1/3 / n = n−2/3 → 0.
n / (n log₂(n)) = 1 / log₂(n) → 0.
Result
log2(n) < n1/3 < 2log₂(n) < log2(n!).
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