1.

The value of ` int _(1)^(e^(2)) (dx)/(x(1+ log x)^(2) ) ` isA. `2/3`B. `1/3`C. `3/2`D. log 2

Answer» Correct Answer - A
Let `l = int_(1)^(e^(2))(dx)/(x(1+log x)^(2))`
Put (1 + log x) `= t rArr dt = (1)/(x) dx`
When x = 1, t = 1
When `x=e^(2), t= 3`
`therefore " " l = int_(1)^(3)(dt)/(t^(2))=[(-1)/(t)]_(1)^(3)=-[(1)/(3)-1]=(2)/(3)`


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