Spinodal decomposition both complete one cycle per second—but they represent different frequencies in the Fourier transform. Hence, frequency no longer measures the number of cycles per unit time, but is closely related.) If A(β) is the amplitude of a Fourier component of wavelength λ and wavenumber β = 2π/λ the spatial variation in composition can be expressed by the Fourier integral: in which the coefficients are defined by the inverse relationship: Substituting, we obtain on equating coefficients: This is an ordinary differential equation that has the solution: in which "A(β)" is the initial amplitude of the Fourier component of wave wavenumber β
What a Time to Be Alive debuted at number one on the US "Billboard" 200, with 375,000 album-equivalent units; it sold 334,000 copies in its first week, with the remainder of its unit count representing the album's streaming activity and track sales during the tracking week. It became both Drake and Future's second albums to chart at number one on the "Billboard" 200 in 2015 ("If You're Reading This It's Too Late" and "DS2", respectively). In its second week it sold 65,000 copies. As of January 27, 2016, "What a Time to Be Alive" has sold 519,000 copies in the United States. The album was certified