Answer is: option1
\( -1 \)Solution:
\( x = \dfrac{2}{t} \)
\( y = \ln t \)
\( \dfrac{dx}{dt} = -\dfrac{2}{t^{2}} \)
\( \dfrac{dy}{dt} = \dfrac{1}{t} \)
Then \( \dfrac{dy}{dx} = \left(\dfrac{1}{t}\right)\left(-\dfrac{t^{2}}{2}\right) = -\dfrac{t}{2} \)
When \( x = 1 \), \( t = 2 \). Then slope \( \dfrac{dy}{dx} = -\dfrac{2}{2} = -1 \)
