Series acot – bug? - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: Series acot – bug? (/thread-21133.html) |
Series acot – bug? - hp-zl - 01-08-2024 08:47 AM All the best in the New Year. Now to the point. HP-G2, firmware 2.1.14730 (2023 04 13) CAS Mode I type: series(acot(x),x,0,6) I receive: order_size(x) But it should be: π/2 - x + x^3/3 - x^5/5 Writing: series(atan(x),x,∞,6) I get the correct result: π/2 - 1/x + (1/x)^3/3 - (1/x)^5/5 + (1/x)^7*order_size(1/x). Is it only like this for me or also for you? Regards. RE: Series acot – bug? - Nigel (UK) - 01-08-2024 09:20 AM Not a bug. acot(x) is discontinuous at x=0 (try plotting it to see this). To get the expansion you want you can use series(acot(x), x, 0, 6, 1) where the final ‘1’ tells the calculator to look for a series valid for x>0. Nigel (UK) RE: Series acot – bug? - hp-zl - 01-09-2024 09:34 AM You're right. I forgot about the fifth argument [Dir] of the series function. Thanks for the reminder. Regards. |