Law of sines - Wikipedia In trigonometry, the law of sines (sometimes called the sine formula or sine rule) is a mathematical equation relating the lengths of the sides of any triangle to the sines of its angles
Beat (acoustics) - Wikipedia Diagram of beat frequency In acoustics, a beat is an interference pattern between two sounds of slightly different frequencies, perceived as a periodic variation in volume, the rate of which is the difference of the two frequencies With tuning instruments that can produce sustained tones, beats can be readily recognized Tuning two tones to a unison will present a peculiar effect: when the
Pulse-repetition frequency - Wikipedia Pulse-repetition frequency (PRF) is the number of times a pulsed activity occurs every second This is similar to cycle per second used to describe other types of waveforms PRF is inversely proportional to time period which is the property of a pulsed wave T = 1 PRF {\displaystyle \mathrm {T} = {\frac {1} {\text {PRF}}}} PRF is usually associated with pulse spacing, which is the distance
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