- Robert F. Kennedy (Wikipedia)
Robert Francis Kennedy (November 20, 1925 – June 6, 1968), also known as RFK, was an American politician and lawyer. He served as the 64th United States attorney general from January 1961 to September 1964, and as a U.S. senator from New York from January 1965 until his assassination in June 1968, when he was running for the Democratic presidential nomination. Like his brothers John F. Kennedy and Ted Kennedy, he was a prominent member of the Democratic Party and is considered an icon of modern American liberalism.
- Cartesian coordinate system (Wikipedia)
In geometry, a Cartesian coordinate system (UK: /kɑːrˈtiːzjən/, US: /kɑːrˈtiːʒən/) in a plane is a coordinate system that specifies each point uniquely by a pair of real numbers called coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, called coordinate lines, coordinate axes or just axes (plural of axis) of the system. The point where they meet is called the origin and has (0, 0) as coordinates.