This gives the meaning of the terms as generally understood in the middle of the 18th century. Robert Hooper's Physician's Vade-Mecum, published in 1812 has been used as a source of terms in the early 19th century; many of the terms mentioned are still in common use.
In either case, the value at x = 0 is defined to be the limiting value sinc(0) = 1. The normalization causes the definite integral of the function over the real numbers to equal 1 (whereas the same integral of the unnormalized sinc function has a value of Ï).
The cosine of a real number t is the x-coordinate of the point P in the following diagram, where | t | is the length of the arc shown. cos t = x-coordinate of the point P sin t = y-coordinate of the point P Graph of the Cosine Function. y = cos x. General Cosine Function. The generalized sine function has the following form: y = A cos[Ï(x - Î±)] + C. 1  A is the amplitude (the height of each peak above the baseline). 2  C is the vertical offset (height of the baseline). 3  P is the period or wavelength (the length of each cycle).