Imaginary Numbers

$Imaginary Numbers$ Imaginary Numbers

Early mathematicians were led to consider purely formal situations involving square roots of negative numbers. Therefore, Heron of Alexandria (circa 100AD) obtained the quantity √-63, and Girolamo Cardan (1545) wrote correctly (5 + √-15)(5 - √-15) = 40. These numbers were considered to be quite meaningless, and the term imaginary was applied to them. They have since become quite important in several branches of modern mathematics and have applications in mechanics and electricity. [RA] {EB}