Question

Find area bounded by $y=e^{-x}$, $x$-axis and $x\ge 0$.

• A. $1$
• B. $2$
• C. $\frac{1}{e}$
• D. $e$

Answer 1

The correct option is A $1$

Area $={\int }_0^{\infty }{e}^{-x}dx={\frac{e^{-x}}{-1}|}_0^{\infty }=\frac{e^{-\infty }}{-1}-\frac{e^0}{-1}=0+1=1$

So, Area $=1$ square units.

Hence, this is the answer.