English Title

Various observations about angles proceeding in geometric progression

Authors

Leonhard Euler

Enestrom Number

561

Fuss Index

153

Original Language

Latin

Content Summary

From the identity sin(s) = 2 sin(s/2) cos(s/2), Euler obtains the infinite product formula sin(s) = s cos(s/2) cos(s/4) cos(s/8) cos(s/16).... He divides by the infinite product and applies logarithmic differentiation to get an infinite sum for 1/s involving cotangents and tangents.

Published as

Collection article

Published Date

1783

Written Date

1773

Original Source Citation

Opuscula analytica, Volume 1, pp. 345-352.

Opera Omnia Citation

Series 1, Volume 15, pp.498-508.

Record Created

2018-09-25

Included in

Mathematics Commons

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