Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Indefinite Integration

Question:

Let $f(x)=\frac{\sqrt{\tan x}}{\sin x \cos x}$ and F(x) is its anti derivative, if $F(\frac{π}{4})$, then F(x) is equal to

Options:

$2(\sqrt{\tan x}+1)$

$2(\sqrt{\tan x}+3)$

$2(\sqrt{\tan x}+2)$

none of these

Correct Answer:

$2(\sqrt{\tan x}+2)$

Explanation:

$F(x)=\int\frac{\sqrt{\tan x}}{\sin x\cos x}dx=\int\frac{\sqrt{\tan x}}{\tan x}\sec^2x\,dx\,\,\,(t=\tan x)$ 

$=\int\frac{1}{\sqrt{t}}dt+c=2\sqrt{t}+c=2\sqrt{\tan x}+c$

Since, $6=F(\frac{π}{4})=2+c$; so c = 4

Hence $F(x)=2(\sqrt{\tan x}+2)$