求助这道题要如何去解决

dx/dt = e^x( sin2t + 2cos2t )；

dy/dt = e^x( cost + sint )；

dy/dx = dy/dt * dt/dx = ( sin2t + 2cos2t )/( cost + sint ) 。

用公式 (uv)'=u'v+uv'

x=(e^t)sin(2t)，y=(e^t)cost

.

dx/dt=(e^t)'sin(2t)+(e^t)[sin(2t)'

=(e^x)sin(2t)+(e^x)*2cos(2t)

=(e^x)[sin(2t)+2cos(2t)]

.

y'=(e^t)'cost+(e^t)(cost)'

=(e^t)cost+(e^t)(-sint)

=(e^t)(cost-sint)

.

dy/dx

=(dy/dt)/(dx/dt)

=(cost-sint)/[sin(2t)+2cos(2t)]