u=x的siny次方二阶

dy/dx=-x/siny-sinydy=xdx两边取积分cosy=ln|x|+c再问：详细些再答：囧算错了-sinydy=xdxS-sinydy=Sxdxcosy=x^2/2+c再问：要一步一步来再

两边求导：cos(x+y)*(1+y')=cosx+cosy*y'y'=(cosx-cos(x+y))/(cos(x+y)-cosy)e^x+1=e^y*y'+y'y'=(e^x+1)/(e^y+1)

两边对x求两次导数：1-y'+1/2cosyy'=0；==>y'=1/(1-cosy/2)0-y''+1/2(y'(-siny)+cosyy'')=0==>y''=y'siny/(cosy-2)再将y

sinx+siny=1/3sinx=1/3-siny(siny)^2+(cosy)^2=1(cosy)^2=1-(siny)^2u=sinx-cos^2yu=(1/3-siny)-[1-(siny)^

t=1/3-sinx-cos^x=sin^x-sinx-2/3=(sinx-1/2)^2-11/12当sinx=1/2时siny为-1/6满足-1≤sinY≤1因为sinx+siny=1/3所以-2/

隐函数的导数求法~

x-y+1/2siny=0两边对x求导得1-y'+1/2cosy*y'=0y'=2/(2-cosy)y''=dy'/dx=(dy'/dy)*(dy/dx)=[-2/(2-cosy)²]*si

sinx+siny=1/3,sinx=1/3-sinysin²x=1/6-2siny/3+sin²yz=siny—cos^2x=siny+sin²x-1=siny+1/6

dsiny+de^x-dxy²=0cosydy+e^xdx-y²dx-2xydy=0cosydy-2xydy=y²dx-e^xdxdy/dx=(y²-e^x)/

u是已知量吗?y=u^2xy′=(u^2x)′=2x(u)^(2x-1)

变为dx/dy=-x+siny公式：对于y'=P(x)y+Q(x),通解为y=(∫{Q(x)e^[-∫P(x)dx]}dx+C)e^[∫P(x)dx]对于dx/dy=-x+siny,P(y)=-1,Q

对x求导得到1-y'+0.5cosy*y'=0所以y'=1/(1-0.5cosy)而继续求导得到y"=-1/(1-0.5cosy)^2*(0.5siny)*y'再代入y'即y"=-1/(1-0.5co

隐函数求导,就是先左右一起求微分,加个d,然后写出多少dx+多少dy=0,移项变成dy/dx=多少的形式就好了

x-y+1/2siny=0F(x,y)=y-x-1/2siny=0F,Fx,Fy在定义域的任意点都是连续的,F(0,0)=0Fy(x,y)>0f'(x)=-Fx(x,y)/Fy(x,y)=1/(1-1

两边关于x求导,注意y是x的函数y'cosy=[1/(x+y)]*(1+y').①解得y'=1/(x+y)÷[cosy-1/(x+y)].②对①两边关于x求导可得y''cosy-(y')²s

dy/dx=（y^2-e^x)/(cosy-2xy)

(1）sinx的取值范围是【-1,1】又siny=1/3-sinx所以可以得到siny的取值范围是【-2/3,4/3】又siny本身的取值范围是【-1,1】故可以得到siny的取值范围是【-2/3,1

siny=1/3-sinx则-1

再问：请问那个f12的二阶导数是怎么来的啊再答：前面两个都来自f1'对x的偏导数再问：哦再问：再问您一下，还是这道题，先对x再对y求二阶连续偏导怎么做啊再问：u先对x再对y再答：再问：多谢再问：请问最

要使等式有意义,则cosx>0,siny>0等式两边取自然对数有ylncosx=xlnsiny等式两边对x求导有d(ylncosx)/dx=d(xlnsiny)/dx[dy*lncosx+y*(1/c