Translations:Sinusoidal motion/10/en

As the vector rotates, its projection ${\rm {\ cos\ }}\omega t$ on the x-axis traces out a cosine curve, and its projection ${\rm {\ sin\ }}\omega t$ on the y-axis traces out a sine curve. Both ${\rm {\ cos\ }}\omega$ and ${\rm {\ sin\ }}\omega t$ represent sinusoidal motion at a fixed frequency $\omega$. Such motion is called either sinusoidal motion or simple harmonic motion. Instead of using a continuous time scale t for the signal, digital processing requires first choosing a time increment $\Delta t$ and then defining the time index n so that time is given by $t{\rm {=}}n\Delta t$. A typical time increment is 0.004 s.