Differentiation Question 428

Question: If $ y=x^{x} $ , then $ \frac{dy}{dx}= $

[AISSE 1984; DSSE 1982; MNR 1979; SCRA 1996; RPET 1996; Kerala (Engg.) 2002]

Options:

A) $ x^{x}\log ex $

B) $ x^{x}( 1+\frac{1}{x} ) $

C) $ (1+\log x) $

D) $ x^{x}\log x $

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Answer:

Correct Answer: A

Solution:

$ y=x^{x} $

Taking $ \log $ on both sides,

Therefore $ \log y=x\log x $

Differentiating with respect to x, we get

Therefore $ \frac{1}{y}\frac{dy}{dx}=1+\log x $ ;
$ \therefore \frac{dy}{dx}=x^{x}(1+\log x)=x^{x}\log ex $ .