大一高数微积分✀一共三个题✀一个100分

2025-05-20 09:35:58
推荐回答(3个)
回答1:

回答2:

回答3:


u=x-y,v=xy,w=x^2+y^2
z'x=f'u*u'x+f'v*v'x+g'w*w'x
=f'u+f'v*y+g'w*2x
z'y=f'u*u'y+f'v*v'y+g'w*w'y
=-f'u+f'v*x+g'w*2y
z''xy=(z'x)'y=(f'u+f'v*y+g'w*2x)'y
=f''u*u'y+f''v*v'y*y+f'v*y'+g''w*w'y*2x
=-f''u+f''v*xy+f'v+g''w*4xy