A set that is not convex is called a non-convex set. A polygon that is not a convex polygon is sometimes called a concave polygon, and some sources more generally use the term concave set to mean a non-convex set, but most authorities prohibit this usage.
In either case you don't need to deal with the absolute value. A rectified sine wave is a periodic signal with a period equal to half of the full sinusoid, I would write the sine in exponential form and integrate over one period to find the series coefficients.
Due to server maintenance we are not accepting new questions at this moment. What Function Accurately Represents The Sine Curve For Orange Light. The wave nature of light : 590 610 nm (orange).  610 700 nm at a point as a function of direction (Ã®Â¸, Ã® ), time (Ã¯) and wavelength(Ã®). I = f(Ã®Â¸, Ã® , Ã¯, Ã®) Accurately represent light intensities coming from different How much sine wave gratings at each frequency are.