This convergence take a look at offers a technique to decide the convergence or divergence of an infinite collection whose phrases are monotonically reducing and non-negative. For a collection a the place a a 0 for all n, it states that the collection converges if and provided that the collection 2a converges. As a traditional instance, contemplate the harmonic collection (1/n), which is understood to diverge. Utility of this take a look at to the collection (1/n) utilizing this take a look at yields the collection (2 * (1/2)) = 1, which additionally diverges, appropriately predicting the divergence of the unique collection.
Its utility lies in its capability to rework sure slowly converging or diverging collection into collection which might be simpler to research. The transformation can considerably simplify the convergence evaluation in circumstances the place direct comparability exams or integral exams are tough to use. Historic significance resides in its early improvement and its lasting affect on the event of extra refined convergence exams. Moreover, it demonstrates a worthwhile approach in mathematical evaluation: reworking an issue into an equal, however extra manageable, type.