# What is the value of integral $\ln x$?

What is the value of integral $\ln x$? Example:

$$\int_2^4 \left(5x^4+2x+5+2\ln x +{1\over x}\right)\,dx$$

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have you tried wikipedia? – user31280 Nov 14 '12 at 14:19
en.wikipedia.org/wiki/… – user31280 Nov 14 '12 at 14:20
I can't find it on wikipedia – lambda23 Nov 14 '12 at 14:21
i just posted a link as comment – user31280 Nov 14 '12 at 14:21

I guess what you are looking for is an antiderivative of $\ln(x)$. It is $$\int \ln(x) \; dx = x\ln(x) -x +C.$$

This should allow you do find the integral.

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Hint: use integration by parts.

Another hint is greyed out below (hover over the box to show it, but only after you've tried!)

$\displaystyle \int \ln x\, dx = \int (1 \times \ln x)\, dx$

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