Question

Find the value of ${\int }_0^{\infty }\left[\frac{2}{e^x}\right]$

• A. \N
• B. ln2
• C. 1
• D. 2

Answer 1

The correct option is B ln2

$I={\int }_0^{\infty }\left[\frac{2}{e^x}\right]dx={\int }_0^{\infty }\left[2e^{-x}\right]dxArea=ln2.1+0=ln2\Rightarrow {\int }_0^{\infty }\left[\frac{2}{e^x}\right]dx=ln2$