Integral Calculus Question 159

Question: $ \int_{{}}^{{}}{\frac{x-2}{x^{2}-4x+3}dx=} $

[MP PET 1987]

Options:

A) $ \log \sqrt{x^{2}-4x+3}+c $

B) $ x\log (x-3)-2\log (x-2)+c $

C) $ \log [(x-3)(x-1)] $

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

Put $ x^{2}-4x+3=t\Rightarrow (2x-4),dx=dt $
$ \Rightarrow (x-2),dx=\frac{1}{2}dt, $ then it reduces to $ \frac{1}{2}\int_{{}}^{{}}{\frac{dt}{t}=\frac{1}{2}\log t+c=\frac{1}{2}\log (x^{2}-4x+3)+c.} $