Vienna (Wikipedia)
Vienna (/viˈɛnə/ vee-EN-ə; German: Wien [viːn]; Austro-Bavarian: Wean [veɐ̯n]) is the capital, most populous city, and one of nine federal states of Austria. It is Austria’s primate city, with just over two million inhabitants. Its larger metropolitan area has a population of nearly 2.9 million, representing nearly one-third of the country’s population. Vienna is the cultural, economic, and political center of the country, the fifth-largest city by population in the European Union, and the most-populous of the cities on the Danube river.- Derivative (Wikipedia)
In mathematics, the derivative shows the sensitivity of change of a function’s output with respect to the input. Derivatives are a fundamental tool of calculus. For example, the derivative of the position of a moving object with respect to time is the object’s velocity: this measures how quickly the position of the object changes when time advances.