-
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)]
如本站内容“对您有用”,欢迎随意打赏,让我们持续更新!
打赏