매개변수 접선 절편

$\displaystyle x = 2 \sqrt{2} \sin t + \sqrt{2} \cos t$, $\displaystyle y = \sqrt{2} \sin t + 2 \sqrt{2} \cos t$ $\displaystyle \frac{dx}{dt} = 2 \sqrt{2} \cos t - \sqrt{2} \sin t$, $\displaystyle \frac{dy}{dt} = \sqrt{2} \cos t - 2 \sqrt{2} \sin t$ $\displaystyle t = \frac{\pi}{4}$이면 $x = 3$, $y = 3$, $\displaystyle \frac{dx}{dt} = 1$, $\displaystyle \frac{dy}{dt} = \mathit{-} 1$ 이므로 접선은 $y - 3 = \mathit{-} ( x - 3 )$, $\therefore$ $y$절편은 6