\begin{align} x &= \cos t + \cos 2t, & y &= \sin t + \sin 2t, & \left(−1, 1\right) \end{align}
Using the above information I found that $\;\frac{dy}{dx}\;$ is:
\begin{align} \dfrac{dy}{dx} &= -\dfrac{\cos t + 2\cos 2t}{\sin t + 2\sin 2t\ } \end{align}
I don't know what to plug in for t, to get my slope. I know that $\,\frac{dy}{dx}\,$ is the slope, but what would go in for t? I solved a similar problem where they gave me the t and asked me to find the slope but I don't know how to handle this one.