Question

$\underset{0}{\overset{\pi /2}{\int }}(\cos x-\sin x)e^{x}dx=$

• A. 0
• B. 1
• C. -1
• D. 2

Answer 1

Answer: (C)

$\underset{0}{\overset{\pi /2}{\int }}[\cos x+(-\sin x)]e^{x}dx$
$={\left[e^x\cos x\right]}_0^{\theta /2}=-1$