第2个回答 2019-01-14
x=φ(t)
dx/dt =φ'(t)
y=ψ(t)
dy/dt =ψ'(t)
dy/dx = (dy/dt)/(dx/dt) = ψ'(t)/φ'(t)
x=(t+1)e^(2t)
dx/dt =( 2t+3) .e^(2t)
e^y + ty = e
e^y . dy/dt + t.dy/dt + y =1
(e^y +t) .dy/dt = 1-y
dy/dt = (1-y)/(e^y +t)
t=0, x=1, y=1
dy/dx
= (dy/dt)/(dx/dt)
=[ (1-y)/(e^y +t)]/[( 2t+3) .e^(2t)]
dy/dx | (x,y)=(1,1) , t=0
=0