2x^2 + y^2 = 44x + 2ydy/dx = 0dy = -2x/y（1,√2）切线的斜率-2/√2 = -√2,法线斜率=1/√2切线方程y-sqrt(2) = -sqrt(2)(x-1),sqrt(2)x + y = 2sqrt(2)法线y-sqrt(2) = (x-1)/sqrt(2)x - sqrt(2)y + 1 = 0...