设曲线由{x=cost y=sint确定则(d^2)y / d(x^2)=
分子是(d^2)y 分母是d(x^2)
那个平方一个在d上,一个在x上。。。求区别与该题答案
设曲线由{x=cost y=sint确定则(d^2)y\/d(x^2)=
"分子是(d^2)y 分母是d(x^2) 那个平方一个在d上,一个在x上。。。":这是高数中二阶全微分的书写形式,表示y’对x求导数。dy\/dx=-cost\/sint,d(dy\/dx)\/dx=(d^2)y\/d(x^2)=-1\/(sint^3)
...x=cost y=sint 那么求d⊃2;y\/dx⊃2;=(d\/dt )(dy\/dx) (dt\/dx...
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求参数方程x=cost和y=sint所确定的函数y=y(x)的二阶导数
“由参数方程x=cost,y=sint所确定的函数y=y(x)的二阶导数”:与求(d^2y)\/(dx^2)的意思是一样的。1、函数y=y(x)的一阶导数的计算:dy\/dx =dy\/dt \/(dx\/dt)=cost\/(-sint)=-ctgt.2、函数y=y(x)的二阶导数的计算:d^2y\/dx^2 =d(-ctgt)\/dx =d(-ctgt)\/dt \/(dx\/dt)=...
设x=cost y=tcost-sint,求d^2y\/dx^2
x=cost dx\/dt = -sint y=tcost -sint dy\/dt = -tsint dy\/dx = dy\/dt \/(dx\/dt)= t d^2y\/dx^2= d\/dx ( dy\/dx)= 1\/(dx\/dt)= -1\/sint
已知参数方程x=cost,y=cost,求dx^2分之d^2y等于多少
答:x=cost,y=cost 所以:x=y 所以:y'=dy\/dx=1 所以:y''=0 即:d²y\/dx²=0
y=cosx\/x^2,求dy\/dsinx,dy\/d(x^2)
如下
设x=ln(1+t),y=arctant,计算(d^2)y\/d(x^2 ) (x=0)
dy\/dx=dy\/dt\/dx\/dt=(1+t)\/(1+t^2)d^2y\/dx^2=d(dy\/dx)\/dt*(dt\/dx)=d(dy\/dx)\/dt*2*(1\/(dx\/dt))=[(1+t^2)-2t(1+t)]\/(1+t^2)^2*(1+t)=(1-2t-t^2)(1+t)\/(1+t^2)^2
设y=x+siny,则[(d^2)y]\/[dx^2]=?
dy=dx+dsiny=dx+cosydy 即y'=dy\/dx=1\/(1-cosy)对x求导 y''=-1\/(1-cosy)²*(1-cosy)'=-siny*y'\/(1-cosy)²=-siny\/(1-cosy)³所以d²y\/dx²=y''=-siny\/(1-cosy)³
x=a cas t ,y=b sin t 求参数方程所确定的函数的二介导数(d^2y)\/(dx...
首先 (d^2y)\/(dx^2)=d(dy\/dx)\/(dx)而 dy\/dx=(dy\/dt ) · dt\/dx)=(dy\/dt )\/(dx\/dt )=b cost*[-1\/(asint)]= -b\/a cot t 所以 d(dy\/dx)\/(dx)=[d(dy\/dx)\/dt ] · (dt\/dx)=[d(dy\/dx)\/dt ] \/(dx\/dt)=b\/a*(1\/sinx...
(d^2)y\/d(x^2) 这个式子怎样化简啊?
由条件x=2t-1得t=(x+1)\/2。带入te^y+y+1=0得:(x+1)e^y+2y+2=0 所以,上式两边对x求导化简得:e^y+[(x+1)e^y+2]dy\/dx=0。再次在等式两边对x求导化简得:[(x+1)e^y+2]*(d^2)y\/d(x^2)+(x+1)e^(2y)(dy\/dx)^2+2e^y(dy\/dx)=0。当t=0时,带回条件知...