Strange behavior on G1 version 2.1.14588 (2021 05 05))

[Joe Horn]

(06-24-2021 02:50 PM)rprosperi Wrote:  Maybe Joe Horn can explain further...

Yes, Home returns 0 for SIN(pi) only by explicitly looking for that expression and pretending to calculate the answer. It's sad and contrary to HP's previous philosophy, but more and more students are expecting to get results like this, so even HP is faking it now.

Also, note that SIN(pi)/pi also returns 0 in Home view if "Intelligent Math" mode is turned on (Home Settings, page 2, only in recent firmware versions). Although it's called "Intelligent Math" Mode, it should really be "Student Stupidity Compensator" Mode. It looks for certain patterns, and passes those through CAS for symbolic simplification. It sometimes returns what students expect, and sometimes doesn't, unpredictably. It will only be a reliable math tool when HP publishes a complete table of the lookup pattern inputs and outputs for "Intelligent Math" mode. And we all know when that will happen.

SIN(pi) and SIN(pi)/pi in CAS view do NOT return 0 when "Exact" mode (in CAS Settings) is turned off, since it uses the truncated 48-bit value of pi. When Exact mode is turned on, the symbol for pi is never evaluated; the expressions are simplified symbolically.

If any of the above is unclear, just holler.