Roulette (curve) in this case, the point lies on the circle then the roulette is a cycloid. A related concept is a glissette, the curve described by a point attached to a given curve as it slides along two (or more) given curves. Formally speaking, the curves must be differentiable curves in the Euclidean plane. The "fixed curve" is kept invariant; the "rolling curve" is subjected to a continuous congruence transformation such that at all times the curves are tangent at a point of contact that moves with the same speed when taken along either curve (another way to express this constraint
What a Pushkin, what a son of a bitch! What a Pushkin, what a son of a bitch! "What a Pushkin, what a son of a bitch!" (; sometimes separated by exclamation mark instead of comma) is a catchphrase and winged word from Alexander Pushkin's correspondence with one of his friends, poet Pyotr Vyazemsky. The phrase commonly expresses a joy after finishing one's work and appears particularly in several Russian literary works. In a letter dated circa November 7 or beginning of October, 1825 Pushkin, celebrating his finished drama "Boris Godunov" wrote to Vyazemsky: That was preceded by what Pushkin wrote to Vyazemsky on July 13 of the same