Definite Integration Question 105

Question: The value of $ \int_0^{2}{\frac{{3^{\sqrt{x}}}}{\sqrt{x}}}dx $ is

[SCRA 1992]

Options:

A) $ \frac{2}{\log 3}.({3^{\sqrt{2}}}-1) $

B) 0

C) $ 2.\frac{\sqrt{2}}{\log 3} $

D) $ \frac{{3^{\sqrt{2}}}}{\sqrt{2}} $

Show Answer

Answer:

Correct Answer: A

Solution:

Put $ \sqrt{x}=t $ or $ \frac{1}{\sqrt{x}}dx=2 $ dt Also, as $ x=0 $ to 2 so, $ t=0 $ to $ \sqrt{2} $

Therefore, $ \int_0^{2}{\frac{{3^{\sqrt{x}}}}{\sqrt{x}}}dx=2\int_0^{\sqrt{2}}{3^{t}}dt=2[ \frac{3^{t}}{\log 3} ]_0^{\sqrt{2}} $

$ =\frac{2}{\log 3}({3^{\sqrt{2}}}-1) $ .