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解題時(shí),我們首先引入極坐標(biāo)變換,設(shè)x=rcosθ,y=rsinθ。由此確定積分區(qū)域,0≤r≤1,0≤θ≤π/2。因此,原積分轉(zhuǎn)換為:∫(0,π/2)dθ∫(0,1)ln(1+r^2)rdr。接下來,我們計(jì)算∫(0,1)ln(1+r^2)rdr。應(yīng)用分部積分法,令u=ln(1+r^2),dv=rdr,則du=(2r/(1+r^2))dr,v=(1/2)r^2。根據(jù)分部積分公式,有:∫ln(1+r^2)rdr = (1/2)r^2ln(1+r^2) - ∫(1/2)r^2(2r/(1+r^2))dr化簡后得:∫ln(1+r^2)rdr = (1/2)r^2ln(1+r^2) - ∫r^2/(1+r^2)dr進(jìn)一步化簡,∫r^2/(1+r^2)dr = ∫(1 - 1/(1+r^2))dr = r - arctan(r) + C因此,∫ln(1+r^2)rdr = (1/2)r^2ln(1+r^2) - (1/2)r^2 + r - arctan(r) + C將上下限代入,得:(1/2)[(1+r^2)ln(1+r^2)-r^2]丨(r=0,1) = (2ln2-1)/2最后,將結(jié)果代入原式,得到:(2ln2-1)π/4。因此,正確答案是C。以上過程僅供參考。