History of The Weather Channel originally generated only text-based products. Radar imagery was added to the units in June of that year, with graphical backgrounds being introduced in July, making the 4000 the first STAR to be capable of generating graphics and the first to incorporate the channel's logo in the forecast segments. Also in 1990, The Weather Channel began including snow condition reports at five minutes after the hour. Largely considered the height of the classic TWC by enthusiasts, The Weather Channel underwent a major graphical revamp (with the introduction of a new slogan, "Weather You Can Always Turn To") on March 6, 1991.
Proof that e is irrational between 2 and 3: We then analyze a blown-up difference "x" of the series representing "e" and its strictly smaller partial sum, which approximates the limiting value "e". By choosing the magnifying factor to be the factorial of "b", the fraction ⁄ and the partial sum are turned into integers, hence "x" must be a positive integer. However, the fast convergence of the series representation implies that the magnified approximation error "x" is still strictly smaller than 1. From this contradiction we deduce that "e" is irrational. Suppose that "e" is a rational number. Then there exist positive integers "a"