Nyquist frequency signal, whereas "Nyquist frequency" is a property of a discrete-time system. When the function domain is time, sample rates are usually expressed in samples per second, and the unit of Nyquist frequency is cycles per second (hertz). When the function domain is distance, as in an image sampling system, the sample rate might be dots per inch and the corresponding Nyquist frequency would be in cycles/inch. Referring again to Figure 1, undersampling of the sinusoid at 0.6 f is what allows there to be a lower-frequency "alias", which is a different function that produces the same set of samples. That
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