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# maths questions watch

1. 1) what does xlnx tend to as x-> infinity ??

I thought it wud tend to x as lnx << x for large x? but i think this is wrong. Can i just say it tends to infinity?

also:

by change of variables but without evaluating the integrals show

INTEGRAL[lnx/x^2] between 1 and infinity equals -INTEGRAL[lnx] between 0 and 1
2. (Original post by Lagz)
1) what does xlnx tend to as x-> infinity ??

I thought it wud tend to x as lnx << x for large x? but i think this is wrong. Can i just say it tends to infinity?

also:

by change of variables but without evaluating the integrals show

INTEGRAL[lnx/x^2] between 1 and infinity equals -INTEGRAL[lnx] between 0 and 1
xlnx just tends to infinity as x-> infinity (if it were x+lnx then you'd be correct, but you are multiplying by x).

As for the second part, try the substitution x=1/u.

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