Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Definite Integration

Question:

\(\int_{2}^{4}\frac{\log x^2}{\log x^2+\log(36-12x+x^2)}dx=\)

Options:

1

2

4

0

Correct Answer:

1

Explanation:

\(I=\int\limits_{2}^{4}\frac{\log x^2}{\log x^2+\log(36-12x+x^2)}dx=\int\limits_{2}^{4}\frac{\log x}{\log x+\log (x-6)}dx\) ...(1)

$I=\int\limits_{2}^{4}\frac{\log (6-x)}{\log x+\log (6-x)}dx$  ...(2) [Using $\int\limits_{a}^{b}f(x)dx=f(a+b-x)dx$]

Eq. (1) + Eq. (2)

$2I=\int\limits_{2}^{4}1dx⇒I=1$