设y=(2t+5)^3,求dy.

设x=e^-t y=e^-2t 求dy/dx 设y=tanx^3-2^-x,求dy 设x=t+arctan t+1,y=t的立方+6t－2,求dy／dx 设x=lnx,y=t∧3,求dy/dX? 设x=t^2+cost,y=1-sint,求dy/dx 设x=3e^-t,y=2e^t,则dy/dx等于多少? 设参数方程{x=（2+t^2),y=t.确定了函数y(x).求dy/dx? 设函数y=y（x）由方程x^2+5xt+4t^3=0 e^y+y(t-1)+lnt=1；求x=1时 dy\ dx 设 {x=2t^3+2 y=e^2t-1 ,求dy/dx,d^2y/dx^2 设x=1+t^2、y=cost 求 dy/dx 和d^2y/dx^2 sint-tcost/4t^3 和 sint-tc 【数学】求导设y=y(x)由{x=arctant,2y-ty^2+e^t =5 }确定,求dy/dx 设函数y=y(x)由x=1-e^t和y=t+e^-t确定,求dy/dx和d^2y/dx^2