4-8-6 4-8-6 Under the Whyte notation for the classification of steam locomotives, a 4-8-6 locomotive would have had four leading wheels, eight coupled driving wheels and six trailing wheels. Other equivalent classifications are: This wheel arrangement was proposed by Lima Locomotive Works in 1949 as a continuation of their "Super Power" concept, essentially an expansion of the 4-8-4. A larger firebox similar to the ones on the 2-6-6-6 locomotives built by Lima would have been fitted, allowing for greater power at speed. Despite promotion by Lima, there is no firm evidence that an example of this type was ever built and
1/2 + 1/4 + 1/8 + 1/16 + ⋯ 1/2 + 1/4 + 1/8 + 1/16 + ⋯ In mathematics, the infinite series is an elementary example of a geometric series that converges absolutely. There are many different expressions that can be shown to be equivalent to the problem, such as the form: 2 + 2 + 2 + ... The sum of this series can be denoted in summation notation as: As with any infinite series, the infinite sum is defined to mean the limit of the sum of the first terms as approaches infinity. Multiplying by 2 reveals a useful relationship: Subtracting from both sides, As approaches