- how do I evaluate this integral?

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URGENT - how do I evaluate this integral?

integral from 1 to 4 of sqrt(x)*ln (x) dx

I tried parts but didn't work

Does anyone know?
 
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Sure it works!
Remember that \frac{d}{dx}\frac{2}{3}x^{\frac{3}{2}}=x^{\frac{1}{2}}=\sqrt{x}
 
The answer is 16/3ln4 - 28/9

WHen i get to int vdu , I have int sqrt(x)*1/x dx, is this right?

Do i just subtract the exponents from here?
 
frasifrasi said:
The answer is 16/3ln4 - 28/9

WHen i get to int vdu , I have int sqrt(x)*1/x dx, is this right?

Do i just subtract the exponents from here?

yes...
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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