Question:
Differentiate
$\frac{\log x}{x}$
Solution:
To find: Differentiation of $\frac{\log x}{x}$
Formula used: (i) $\left(\frac{u}{v}\right)^{\prime}=\frac{u^{\prime} v-u v^{\prime}}{v^{2}}$ where $v \neq 0$ (Quotient rule)
(ii) $\frac{d \log x}{d x}=\frac{1}{x}$
Let us take u = logx and v = x
$u^{\prime}=\frac{d u}{d x}=\frac{d(\log x)}{d x}=\frac{1}{x}$
$v^{\prime}=\frac{d v}{d x}=\frac{d(x)}{d x}=1$
Putting the above obtained values in the formula:-
$\left(\frac{u}{v}\right)^{\prime}=\frac{u^{\prime} v-u v^{\prime}}{v^{2}}$ where $v \neq 0$ (Quotient rule)
$\left(\frac{\log x}{x}\right)^{\prime}=\frac{\frac{1}{x} \times x-\log x \times 1}{(x)^{2}}$
$=\frac{1-\log x}{x^{2}}$
Ans) $=\frac{1-\log x}{x^{2}}$