x = t - ln(1+t) y = t^3 + t^2 求dy/dx

问题描述:

x = t - ln(1+t) y = t^3 + t^2 求dy/dx

dy/dx=(dy/dt)/(dx/dt)=(3t^2+2t)/[1-1/(1+t))]=(3t^2+2t)/[t/(1+t))]=(3t+2)(t+1)=3t^2+5t+2