prosta całka do obliczenia..

[TobiWan]

\(\displaystyle{ \int\frac{x}{\sqrt{x^{2}+9}}dx}\)

[kerajs]

\(\displaystyle{ \int\frac{x}{\sqrt{x^{2}+9}} \mbox{d}x =\left[ t=x^2+9\right]=\int \frac{ \frac{ \mbox{d}t}{2} }{ \sqrt{t} }= \sqrt{t} +C=\sqrt{x^{2}+9}+C}\)