x^2+y^2-2x-2y+1=0(x-1)^2+(y-1)^2=1设x/a+y/b=1(a>2,b>2)直线与圆相切|1/a+1/b-1|/√(1/a^2+1/b^2)=1ab+2=2a+2b由均值不等式ab+2≥4√(ab)设√(ab)=t>2t^2-4t+2≥0t≤2-√2或t≥2+√2则t≥2+√2ab≥6+4√2当且仅当a...