Question

Consider the following functions, where nn is a positive integer.

n1/3,log⁡(n),log⁡(n!),2log⁡(n)n^{1/3}, \quad \log(n), \quad \log(n!), \quad 2^{\log(n)}

Which one of the following options lists the functions in increasing order of asymptotic growth rate?

Note: Assume the base of log⁡\log to be 22.

Choose one option
Official answer and solution
Official answer
A
From
Official GATE 2026 answer key

Solution

Simplify 2log⁡2(n)=n2^{\log_2(n)} = n and log⁡2(n!)=Θ(nlog⁡n)\log_2(n!) = \Theta(n \log n), then order the four growth rates.

Since the logarithm base is 22:

  1. log⁡2(n)\log_2(n) grows logarithmically.
  2. n1/3n^{1/3} grows polynomially with exponent 1/31/3.
  3. 2log⁡2(n)=n2^{\log_2(n)} = n grows linearly (exponent 11).
  4. By Stirling's approximation, log⁡2(n!)=Θ(nlog⁡n)\log_2(n!) = \Theta(n \log n), which grows faster than nn.

Thus the increasing order of asymptotic growth is:

log⁡(n)≺n1/3≺2log⁡(n)≺log⁡(n!)\log(n) \prec n^{1/3} \prec 2^{\log(n)} \prec \log(n!)
Final answer

Option (A)

Common trap

Mistaking 2log⁡2(n)2^{\log_2(n)} for an exponential function instead of nn.

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

Source

Paper
GATE 2026 Computer Science and Information Technology - Session 2 (CS2)
Question
24 of 65
Section
Computer Science and Information Technology

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