Sinusoid

sinusoid

[′sī·nə‚sȯid]

(anatomy)

Any of the relatively large spaces comprising part of the venous circulation in certain organs, such as the liver.

(mathematics)

sine curve

Sinusoid

 

(or sine curve), the graph of the function y = sin x. It is a plane curve (see Figure 1) representing the variation in the sine as the argument, or angle, changes. A sinusoid intersects the x-axis at the points 180°k (or πk) and has maxima at the points 90° + 360°k (or π/2 + 2-πk) and minima at the points - 90° + 360°k (or - π/2 + 2πk), where k = 0, ± 1.....

Figure 1

The curve defined by the equation y = A sin (ωx + Φ₀) is also sometimes called a sinusoid. The relation between this curve and the curve y = sin x is as follows: first, the x-coordinates of the points of y = sin x are increased by a factor of ω; second, the y-coordinates of the points of y = sin x are increased by a factor of A; and third, the curve is translated by an amount - Φ₀/ω along the x-axis. The number A is called the amplitude, ω is called the angular frequency, and Φ/₀ is called the initial phase angle. The sinusoid is of great importance in the theory of oscillations. [23–1296–]