$\frac{ v ^{2}}{\omega^{2}}+ x ^{2}= A ^{2}$
$\frac{ v ^{2}}{(\omega A )^{2}}+\frac{ x ^{2}}{ A ^{2}}=1$
This is an equation of an ellipse.
If the position and velocity of the particle at $t=0\, {s}$ are $2\, {cm}$ and $2\, \omega \,{cm} \,{s}^{-1}$ respectively, then its amplitude is $x \sqrt{2} \,{cm}$ where the value of $x$ is ..... .