∵f(n) is strictly increasing in (−3,−1) and (0,2) because f′(n) is positive, for n∈(−3,−1)∪(0,2) and f is strictly decreasing in (−1,0). ∵f(−1) or f(2) is the maximum value of the function and f(−1)=1 and f(2)=22/3 ∴‌3√x=22/3⇒x=4