由画图知,面积=梯形面积-y=1/x的积分面积积分区域:1/x=2x,x=√2/2y1=1/x=√2,y2=2x=2√2S=(√2+2√2)(3-√2/2)/2-S3,√2/2(1/x)dx=3√2(3-√2/2)/2-lnx|3,√2/2=3(3√2-1)/1-(ln3-ln(√2/2)=3(3√2-1)-(ln3+1/2ln2)...