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The interval in which f(x)=xlog⁡xf(x)=\frac{x}{\log x} is increasing, is:

Solution

✅ Correct Option: 4

f′(x)=log⁡x−1(log⁡x)2f'(x)=\frac{\log x-1}{(\log x)^2}.

The denominator is always positive on the domain, so f′>0f'>0 requires log⁡x>1\log x>1, that is x>ex>e.

Hence ff increases on (e,∞)(e,\infty).

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