WP 34S vs. DM42 decimal128 differences?

[rkf]

(03-26-2018 09:51 PM)Nigel (UK) Wrote:  This is addressed to Pauli:

I've noticed that sin (pi radians) in double-precision mode on the WP34S is only correct to 17 significant figures. ...

Although I'm not Pauli but the original poster, I don't get the point here. Typing in Rad mode pi sin gives on both WP 34S DBLON, and DM42, a result of about -1.158E-34.

For me as a plain user this result seems to have nevertheless 34 significant figures, all of them zeroes (one before the decimal point, and 33 thereafter).

Or do you compare the (exact) result of taking sin of a number, which is exactly pi rounded to 34 significant figures (thus to be expected in the ballpark around +/- 1E-34) with the result the calculator gives, and then -1.158028306006248941790250554076922E-34 itself is only correct to 17 figures? But that would be no problem at all for me.