題目 6. (10%)(10\%)(10%) Evaluate ∬Dln(x2+y2)x2+y2 dx dy,\iint_D \frac{\ln(x^2+y^2)}{\sqrt{x^2+y^2}}\,dx\,dy,∬Dx2+y2ln(x2+y2)dxdy, where D={(x,y):1≤x2+y2≤e}D=\{(x,y):1\le x^2+y^2\le e\}D={(x,y):1≤x2+y2≤e}. 解答
