The area of the region bounded by the curve $y=\log x, x$ -axis and the lines $x=1, x=e$ is

The area of the region bounded by the curve $y=\log x, x$ -axis and the lines $x=1, x=e$ is
  1. $\frac{1}{e}$ Sq. Units
  2. 1 Sq. Units
  3. 4 sq. Units
  4. $\frac{1}{2}$ Sq. Units

Solution

Required area is shaded. $\begin{aligned} \therefore \mathrm{A} &=\int_{1}^{\mathrm{e}} \log \mathrm{x} \mathrm{dx}=\int_{1}^{\mathrm{e}}(\log \mathrm{x})(1) \mathrm{dx} \\ &=[\mathrm{x} \log (\mathrm{x})]_{1}^{\mathrm{e}}-\int_{1}^{\mathrm{e}} \frac{1}{\mathrm{x}} \times \mathrm{x} \mathrm{dx} \\ &=[\mathrm{e}(\log \mathrm{e})-0]-[\mathrm{x}]_{1}^{\mathrm{e}}=\mathrm{e}-(\mathrm{e}-1)=1 \end{aligned}$

Asked in: MHT CET 2020 (14 Oct Shift 1)

Practice more Area Under Curves questions on Aicharya