Problem

Here is a set of equations defined parametrically in terms of \(t\).

\[\begin{align*} x &= 1+ 4 \cos t \\ y &= t+ 3 \sin t \end{align*}\]
\[\begin{align*} x &= 2 \cos t \\ y &= \sin 2t \end{align*}\]
\[\begin{align*} x &= t^2 \\ y &= t^3-4t \end{align*}\]
\[\begin{align*} x &= t^2+t+1 \\ y &= 2t^2-2 \end{align*}\]
\[\begin{align*} x &= t^3-t \\ y &= t^3-3t \end{align*}\]
\[\begin{align*} x &= 2+ 3 \cos t \\ y &= 4+ 5 \sin t \end{align*}\]

Using the interactive below or the printable cards, match up each equation (blue card) with

  • the location of a stationary point on the curve (green card),

  • the location of a critical point on the curve where the tangent is vertical (pink card),

  • its graph (white card).

(Note that some of the curves have other stationary points and critical points that do not appear on cards.)

\[\begin{align*} x &= 2+ 3 \cos t \\ y &= 4+ 5 \sin t \end{align*}\]
\[\begin{align*} x &= t^3-t \\ y &= t^3-3t \end{align*}\]
\[\begin{align*} x &= t^2+t+1 \\ y &= 2t^2-2 \end{align*}\]
\[\begin{align*} x &= t^2 \\ y &= t^3-4t \end{align*}\]
\[\begin{align*} x &= 2 \cos t \\ y &= \sin 2t \end{align*}\]
\[\begin{align*} x &= 1+ 4 \cos t \\ y &= t+ 3 \sin t \end{align*}\]

Stationary point at \[x=1\]

Stationary point at \[x=0\]

Stationary point at \[x=-\frac{1}{3}\]

Stationary point at \[x=\sqrt{2}\]

Stationary point at \[x=2\]

Stationary point at \[x=\frac{4}{3}\]

Critical point at \[(0,0)\]

Critical point at \[(5,4)\]

Critical point at \[\left(\frac{2}{3\sqrt{3}},\frac{8}{3\sqrt{3}}\right)\]

Critical point at \[(2,0)\]

Critical point at \[(5,0)\]

Critical point at \[\left(\frac{3}{4},-\frac{3}{2}\right)\]

curve like a leaning cubic
curve like a greek alpha
curve like an ellipse
curve like a coiled spring
curve like an infinity sign
curve like a leaning parabola