y=2x 则 d^2y/dx^2 = 2 是否正确?

d/dx((x^2+y^2)^2)=d/dx(x^2-y^2),求（化简）dy/dx=? 设函数y=x^4-8x^2,则 d^2y/dx^2=? 反函数的二阶导数疑问设dy/dx=y',则dx/dy=1/y',应视为y的函数则d2x/dy2=d(dx/dy)/dy（定义）=d(1/(dy/dx)) / dy=d(1/(dy/dx))/dx * dx/dy（复合函数求导,x是中间变量）=-y''/(y')^2 * (1/y')=-y''/(y')^3d(1/(dy/dx))/dx * dx/dy y=2x 则 d^2y/dx^2 = 2 是否正确? 设y=x+siny,则[(d^2)y]/[dx^2]=? 已知dx/dy=1/y′,求d（2）y/d x^2? 设x=e^(-t) 试变换方程x^2 d^2y/dx^2 +xdy/dx+y=0 微分方程(d^2y/dx^2)^2=x^2*(dy/dx)怎么解rt 求解微分方程d^2y/dx^2-dy/dx=x (x^2)dy+（y^2)dx=dx-dy y=[sin(x^4)]^2,则dy/dx=?,dy^2/dx^2=?,dy/d(x^2)=? 二次微分中关于dx dx^2 (dx)^2的疑问二次微分定义公式是：d(dy/dx)/dx=d^2y/dx^2,我想问：d(dy/dx)/dx本来是等于d(dy)/[dx*d(dx)],接着等于d^2y/(dx*d^2x),接下来为什么就等于d^2y/dx^2啊!我想问问：为什么dx^2=dx* y=(1+x^2)arctan x 用MATLAB求(d^2*y)/dx^2 设y=ln(x+根号(x^2+4),求d^2y/dx^2 求解一阶微分方程：(3x+2cosy)dx-x sin y d y=0 求微分 方程y-2x=(x-y)ln(x-y) 求dy/ dx 和d^2y/ dx^2如题··设函数y=y(x) 由方程y-2x=(x-y)ln(x-y)所确定 求dy/ dx 和d^2y/ dx^2有公式什么的···谢谢··· dy/dx=2y/x+3x/2y 设y=y(x)由方程y-xe^y=1所确定,则d^y/dx^2|x=0得多少