Definite Integration Question 75

Question: Area of the region bounded by the curve $ y=\tan x, $ tangent drawn to the curve at $ x=\frac{\pi }{4} $ and the x-axis is

[DCE 2001]

Options:

A) $ \frac{1}{4} $

B) $ \frac{4}{3} $

C) $ \log \sqrt{2}-\frac{1}{4} $

D) None of these

Show Answer

Answer:

Correct Answer: D

Solution:

Shaded area $ =\int_0^{\pi /2}{\tan xdx} $

$ =[\log \sec x]_0^{\pi /4} $

$ =\log \sec (\pi /4)-\log \sec 0 $

$ =\log \sqrt{2}-\log 1 $

$ =\log \sqrt{2} $ .