下列函数的全微分：u=In(x^2-y^2-2^2)

下列函数的全微分：u=In(x^2-y^2-2^2)
下列函数的全微分：u=In(x^2-y^2-2^2)

下列函数的全微分：u=In(x^2-y^2-2^2)
du = ux`dx + uy`dy
ux` = 2x/(x^2-y^2-2^2) [此为u对x的偏导数]
uy` = -2y/(x^2-y^2-2^2) [此为u对y的偏导数]
所以du = 2x/(x^2-y^2-2^2) * dx - 2y/(x^2-y^2-2^2) * dy

du=2xdx/(x^2-y^2-4)-2ydy/(x^2-y^2-4)