Gujarat BoardEnglish MediumSTD 12 ScienceMathsIntegrals1 Mark
MCQ
$\int_0^1 \log \left(\frac{1}{x}-1\right) d x$ is equal to :
✓
$0$
B
1
C
$\log 2$
D
$\log \frac{3}{2}$
✓
Answer
Correct option: A.
$0$
(A)Let $ \begin{aligned} I & =\int_0^1 \log \left(\frac{1}{x}-1\right) d x=\int_0^1 \log \left(\frac{1-x}{x}\right) d x \ldots(1) \\ I & =\int_0^1 \log \left(\frac{1-x}{x}\right) d x \\ & =\int_0^1 \log \left(\frac{1-(1-x)}{(1-x)}\right) d x \text { From Property } P_5 \end{aligned} $ $ \begin{aligned} I & =\int_0^1 \log \left(\frac{1-1+x}{(1-x)}\right) d x=\int_0^1 \log \left(\frac{x}{(1-x)}\right) d x \\ I & =-\int_0^1 \log \left(\frac{1-x}{x}\right) d x \\ I & =-I \\ 2 I & =0 \therefore I=0 \end{aligned} $ Hence option (A) is correct.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.