求xy+cosy^2=x^2的导数y’

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求xy+cosy^2=x^2的导数y’
求xy+cosy^2=x^2的导数y’

求xy+cosy^2=x^2的导数y’
xy+cosy^2=x^2.两边同时对x求导得:
y+xy'-2y'*y*sin(y^2)=2x.(cos(y^2)关于x的导数是:-2y'*y*sin(y^2))
y'(x-2ysin(y^2))=2x-y.
所以:y'=(2x-y)/(x-2ysin(y^2)).

xy+cosy^2-x^2=0
x'y+xy'+(cosy^2)'-2x=0
y+xy'-2siny*y'-2x=0
xy'-2siny*y'=2x-y
y'=(2x-y)/(x-2siny)
注:因为y是关于x的函数,所以(cosy^2)'=-2siny*y'

隐函数的求导:y+xy'-2yy'siny^2=2x 所以y'=2x-y/(x-2ysiny^2)