Question Number 138275 by mathmax by abdo last updated on 11/Apr/21
![1)calculate U_n =∫∫_([(1/n),1]^2 ) (2x+3y)(√(x^2 +y^2 ))dxdy 2)find ∫∫_(]0,1]^2 ) (2x+3y)(√(x^2 +y^2 ))dxdy](https://www.tinkutara.com/question/Q138275.png)
$$\left.\mathrm{1}\right)\mathrm{calculate}\:\mathrm{U}_{\mathrm{n}} =\int\int_{\left[\frac{\mathrm{1}}{\mathrm{n}},\mathrm{1}\right]^{\mathrm{2}} } \:\:\:\left(\mathrm{2x}+\mathrm{3y}\right)\sqrt{\mathrm{x}^{\mathrm{2}} \:+\mathrm{y}^{\mathrm{2}} }\mathrm{dxdy} \\ $$$$\left.\mathrm{2}\right)\mathrm{find}\:\int\int_{\left.\right]\left.\mathrm{0},\mathrm{1}\right]^{\mathrm{2}} } \left(\mathrm{2x}+\mathrm{3y}\right)\sqrt{\mathrm{x}^{\mathrm{2}} +\mathrm{y}^{\mathrm{2}} }\mathrm{dxdy} \\ $$