Michael Hardy. On Tangents and Secants of Infinite Sums. The American Mathematical Monthly, 123(7):701-703, 2016. [doi]
@article{Hardy16, title = {On Tangents and Secants of Infinite Sums}, author = {Michael Hardy}, year = {2016}, url = {https://www.tandfonline.com/doi/abs/10.4169/amer.math.monthly.123.7.701}, researchr = {https://researchr.org/publication/Hardy16}, cites = {0}, citedby = {0}, journal = {The American Mathematical Monthly}, volume = {123}, number = {7}, pages = {701-703}, }