求助!!!!!灌水直接举报
解(1). f(x,y)=x^2-6xy+2y^2+10x+2y,一阶偏导为:fx=2x-6y+10,fy=-6x+4y+2
二阶偏导:fxy=-6
(3)f(x,y)=ln(x^2+y),一阶偏导:fx=2x/(x^2+y),fy=1/(x^2+y)
二阶偏导:fxy=-2x/(x^2+y)^2
解答如下