題目 Problem (H). Find the plane tangent to the surface x3+y+z2−xy3z4=8x^3+y+z^2-xy^3z^4=8x3+y+z2−xy3z4=8 at the point (2,1,1)(2,1,1)(2,1,1). Answer. (9)‾\underline{\quad(9)\quad}(9). 解答
