hp9830a

[Andy Delano]

I recently uncovered an hp9830a which still works. I've been playing around with it and noticed that it has the following trig functions:

sin(x)
cos(x)
tan(x)
atn(x)

It doesn't have built in functions for arcsin or arccos. I was wondering why. Does anyone know?

Thanks,

Andy

[Jim L]

I'm not sure if they were trying to save space in the interpreter or, because BASIC was originally designed as a teaching language, trying to force the programmers to think about how to generate ASIN and ACOS from the other functions. Maybe both.

[John Ioannidis]

RTFM! (it is available on this very site!)
Page 2-18: "The arcsine and arccosine functions are not directly obtainable on the Model 30. However, they can be easily obtained by using the following formulas..."

/ji, who hasn't used a 9830 in 20 years