已知 x=e^t ,dy/dx=dy/xdt .分析变换具体步骤 d^2y/dx^2=(d^2y/dt^2-dy/dt)/x^2 ,d^y3/dx^3

dy/dx=e^(-x^2) 已知 x=e^t ,dy/dx=dy/xdt .分析变换具体步骤 d^2y/dx^2=(d^2y/dt^2-dy/dt)/x^2 ,d^y3/dx^3 设dy/dx∫(0,e^-x)f(t)dt=e^x,f(x)=? dy/dx=x+y x=f(t) y=g(t) 为什么dy/dx=(dy/dt)*(dt/dx) x=2t+cost y=t+e^t 求dy/dx把t消除 dy/dx,y=(1+x+x^2)e^x 设x=e'sin t,y=e'cos t,求dy/dx. 设x=e^-t y=e^-2t 求dy/dx 设x=3e^-t,y=2e^t,则dy/dx等于多少? 设x=3e^-t,y=2e^t,则dy/dx等于多少? 参数方程x=(t-1)e^t,y=1-t^4,求dy/dx d(t(dy/dt))/dx为什么等于t² d²y/dt²+t dy/dt作变量代换x=lnt简化方程d^2y/dx^2-dy/dx+e^2x*y=0x=lntdx/dt=1/tdy/dx=(dy/dt)/(dx/dt)=t dy/dtd²y/dx²=[d/dt(dy/dx)]/(dx/dt)=t² d²y/dt²+t dy/dt代入d^2y/dx^2- 微分方程(x+y)(dx-dy)=dx+dy的通解 (x^2)dy+（y^2)dx=dx-dy 解方程 x(dy/dx)^3=(1+dy/dx) y=e^(x^x) dy/dx=? 微分方程 dy/dx=(e^y+3x)/x^2