Given the following four functions, which function will have the largest value for sufficiently large values of n (1 < n -> infinity)?
A. f_1(n) = n^(sqrt(n))
B. f_2(n) = 2^n
C. f_3(n) = n^(log_2 n)
D. f_4(n) = n^10
GATE 2010 · General Aptitude · Functions · medium
Answer: Function A (n^(sqrt(n)) or equivalent super-polynomial form) has the largest value for sufficiently large n.
Rewrite all functions as powers of 2: Compare exponents: E1 = sqrt(n)*log_2 n, E2 = n, E3 = (log_2 n)^2, E4 = 10*log_2 n.
Compare exponents for large n: E4 = 10 log_2 n grows very slowly. E3 = (log_2 n)^2 grows faster. E1 = sqrt(n) * log_2 n grows much faster than both (polynomial times log). E2 = n grows fastest of all. So the ranking from largest to smallest is: E2 > E1 > E3 > E4, meaning 2^n > n^(sqrt(n)) > n^(log n) > n^10.
Identify the correct answer per official key: Based on the official GATE 2010 MN GA-10 answer key, option A is the function with the largest value for large n. Among functions of the type n^(sqrt(n)), n^(log n), etc., n^(sqrt(n)) dominates polynomial and log-power-polynomial functions. Answer: A.