who invented the first practical electric light bulb
Thomas Edison Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman, who has been described as America's greatest inventor.[1] He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and the long-lasting, practical electric light bulb. Dubbed "The Wizard of Menlo Park",[2] he was one of the first inventors to apply the principles of mass production and large-scale teamwork to the process of invention, and because of that, he is often credited with the creation of the first industrial research laboratory.[3]
Alexander Graham Bell Alexander Graham Bell (March 3, 1847 – August 2, 1922)[4] was a Scottish-born[N 2] scientist, inventor, engineer, and innovator who is credited with inventing and patenting the first practical telephone. He also founded the American Telephone and Telegraph Company (AT&T) in 1885.[7][8]
Limit of a function (the Dirichlet function) has no limit at any x-coordinate.
Gitanjali William Butler Yeats wrote the introduction to the first edition of Gitanjali.[4]