We have,
∫dxx(lnx)(ln(lnx))........(lnlnlnlnx......lnx)(20times)
Then,
We know that,
∫dxx=lnx
So, according to given question
∫dxx(lnx)(ln(lnx))........(lnlnlnlnx......lnx)(20times)
ln(xlnx(ln(lnx))........(lnlnlnlnx.....lnx)20times)
lnlnlnlnx.....lnx(21times)
Hence this is the answer.