4-8-8-2 4-8-8-2 Under the Whyte notation for the classification of steam locomotives, a 4-8-8-2 is a locomotive with four leading wheels, two sets of eight driving wheels, and a two-wheel trailing truck. Other equivalent classifications are:<br> UIC classification: 2DD1 (also known as German classification and Italian classification)<br> French classification: 240+041<br> Turkish classification: 46+45<br> Swiss classification: 4/6+4/5 The equivalent UIC classification is refined to (2'D)D1' for Mallet locomotives. A locomotive of that length must be an articulated locomotive; meaning all have a joint between the first and second groups of driving wheels. All examples of this type are cab forwards. Normally, the
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