Evaluate: `int(logx)/xdx`

Explanation

Let `t = tan theta`

Then, `sinx = (2tan theta)/(1+tan^2theta)`

As, `(2tan theta)/(1+tan^2theta) = sin2theta`,

`=> sin x = sin2theta`

`=> x= 2npi+2theta`

`=>dx/ (d theta) = 2 `

Now, `tan y = (2tan theta)/(1-tan^2theta)`

As, `(2tan theta)/(1- tan^2theta) = tan2theta`,

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