Kinetic theory of gases
A Lissajous figure is a graph of the system of Parametric equation. which
describe the superposition of two perpendicular oscillations in x and y
directions of different angular frequency (a and b). The resulting familys
of curves was investigated by Nathaniel Bowditch in 1815, and later in
more detail in 1857 by Jules Antoine Lissajous (for whom it has been
named). Such motions may be considered as a particular of kind of complex
harmonic motion.
When Frequencies are same.
\begin{align*}
\frac{x}{a}&=\sin(\omega t +\phi)~~~\frac{y}{a}=\sin\omega t\\
\frac{x}{a}&=\sin\omega t\cos\phi + \cos\omega t\sin\phi\\
\frac{x}{a}&=\frac{y}{b}\cos\phi+\sqrt{1-(\frac{y}{b})^2}\sin\phi\\
\frac{x}{a}-\frac{y}{b}\cos\phi&=\sqrt{1-\left( \frac{y}{b} \right)^2}\sin\phi\\
\frac{x^2}{a^2}+\frac{y^2}{b^2}\cos^2\phi-2\frac{xy\cos\phi}{ab}&=\sin^2\phi-\frac{y^2}{b^2}\sin^2\phi\\
\frac{x^2}{a^2}-2\frac{xy\cos\phi}{ab}+\frac{y^2}{b^2}\left(\sin^2\phi+\cos^2\phi \right)=\sin^2\phi\\
\frac{x^2}{a^2}-2\frac{xy\cos\phi}{ab}+\frac{y^2}{b^2}=\sin^2\phi\\
\frac{x^2}{a^2}+\frac{y^2}{b^2}-2\frac{xy\cos\phi}{ab}=\sin^2\phi\\
\end{align*}
$$\frac{x}{a}=\sin(\omega t+\phi)~~~~~~~~~~\frac{y}{b}=\sin(\omega t)$$
$$\langle v \rangle=\sqrt{\frac{8K_BT}{\pi m}}=\sqrt{\frac{8RT}{\pi M}}=\sqrt{2.54\frac{RT}{M}}$$